diff --git a/CHANGES.rst b/CHANGES.rst
index 0b8d2cfd..64d5770c 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -3,6 +3,24 @@ Version 2.3.0
 
 Unreleased
 
+-   Remove previously deprecated code. :pr:`4995`
+
+    -   The ``push`` and ``pop`` methods of the deprecated ``_app_ctx_stack`` and
+        ``_request_ctx_stack`` objects are removed. ``top`` still exists to give
+        extensions more time to update, but it will be removed.
+    -   The ``FLASK_ENV`` environment variable, ``ENV`` config key, and ``app.env``
+        property are removed.
+    -   The ``session_cookie_name``, ``send_file_max_age_default``, ``use_x_sendfile``,
+        ``propagate_exceptions``, and ``templates_auto_reload`` properties on ``app``
+        are removed.
+    -   The ``JSON_AS_ASCII``, ``JSON_SORT_KEYS``, ``JSONIFY_MIMETYPE``, and
+        ``JSONIFY_PRETTYPRINT_REGULAR`` config keys are removed.
+    -   The ``app.before_first_request`` and ``bp.before_app_first_request`` decorators
+        are removed.
+    -   ``json_encoder`` and ``json_decoder`` attributes on app and blueprint, and the
+        corresponding ``json.JSONEncoder`` and ``JSONDecoder`` classes, are removed.
+    -   The ``json.htmlsafe_dumps`` and ``htmlsafe_dump`` functions are removed.
+
 -   Use modern packaging metadata with ``pyproject.toml`` instead of ``setup.cfg``.
     :pr:`4947`
 -   Ensure subdomains are applied with nested blueprints. :issue:`4834`
diff --git a/docs/api.rst b/docs/api.rst
index afbe0b79..bf37700f 100644
--- a/docs/api.rst
+++ b/docs/api.rst
@@ -270,12 +270,6 @@ HTML ``<script>`` tags.
     :members:
     :member-order: bysource
 
-.. autoclass:: JSONEncoder
-   :members:
-
-.. autoclass:: JSONDecoder
-   :members:
-
 .. automodule:: flask.json.tag
 
 
diff --git a/docs/config.rst b/docs/config.rst
index 9db2045f..d71f0326 100644
--- a/docs/config.rst
+++ b/docs/config.rst
@@ -65,18 +65,6 @@ Builtin Configuration Values
 
 The following configuration values are used internally by Flask:
 
-.. py:data:: ENV
-
-    What environment the app is running in. The :attr:`~flask.Flask.env` attribute maps
-    to this config key.
-
-    Default: ``'production'``
-
-    .. deprecated:: 2.2
-        Will be removed in Flask 2.3. Use ``--debug`` instead.
-
-    .. versionadded:: 1.0
-
 .. py:data:: DEBUG
 
     Whether debug mode is enabled. When using ``flask run`` to start the development
@@ -271,52 +259,6 @@ The following configuration values are used internally by Flask:
 
     Default: ``None``
 
-.. py:data:: JSON_AS_ASCII
-
-    Serialize objects to ASCII-encoded JSON. If this is disabled, the
-    JSON returned from ``jsonify`` will contain Unicode characters. This
-    has security implications when rendering the JSON into JavaScript in
-    templates, and should typically remain enabled.
-
-    Default: ``True``
-
-    .. deprecated:: 2.2
-        Will be removed in Flask 2.3. Set ``app.json.ensure_ascii``
-        instead.
-
-.. py:data:: JSON_SORT_KEYS
-
-    Sort the keys of JSON objects alphabetically. This is useful for caching
-    because it ensures the data is serialized the same way no matter what
-    Python's hash seed is. While not recommended, you can disable this for a
-    possible performance improvement at the cost of caching.
-
-    Default: ``True``
-
-    .. deprecated:: 2.2
-        Will be removed in Flask 2.3. Set ``app.json.sort_keys``
-        instead.
-
-.. py:data:: JSONIFY_PRETTYPRINT_REGULAR
-
-    :func:`~flask.jsonify` responses will be output with newlines,
-    spaces, and indentation for easier reading by humans. Always enabled
-    in debug mode.
-
-    Default: ``False``
-
-    .. deprecated:: 2.2
-        Will be removed in Flask 2.3. Set ``app.json.compact`` instead.
-
-.. py:data:: JSONIFY_MIMETYPE
-
-    The mimetype of ``jsonify`` responses.
-
-    Default: ``'application/json'``
-
-    .. deprecated:: 2.2
-        Will be removed in Flask 2.3. Set ``app.json.mimetype`` instead.
-
 .. py:data:: TEMPLATES_AUTO_RELOAD
 
     Reload templates when they are changed. If not set, it will be enabled in
@@ -381,14 +323,13 @@ The following configuration values are used internally by Flask:
 .. versionchanged:: 2.2
     Removed ``PRESERVE_CONTEXT_ON_EXCEPTION``.
 
-.. versionchanged:: 2.2
-    ``JSON_AS_ASCII``, ``JSON_SORT_KEYS``,
-    ``JSONIFY_MIMETYPE``, and ``JSONIFY_PRETTYPRINT_REGULAR`` will be
-    removed in Flask 2.3. The default ``app.json`` provider has
+.. versionchanged:: 2.3
+    ``JSON_AS_ASCII``, ``JSON_SORT_KEYS``, ``JSONIFY_MIMETYPE``, and
+    ``JSONIFY_PRETTYPRINT_REGULAR`` were removed. The default ``app.json`` provider has
     equivalent attributes instead.
 
-.. versionchanged:: 2.2
-    ``ENV`` will be removed in Flask 2.3. Use ``--debug`` instead.
+.. versionchanged:: 2.3
+    ``ENV`` was removed.
 
 
 Configuring from Python Files
diff --git a/src/flask/__init__.py b/src/flask/__init__.py
index 185a465a..cc953ab1 100644
--- a/src/flask/__init__.py
+++ b/src/flask/__init__.py
@@ -51,7 +51,7 @@ def __getattr__(name):
         from .globals import __app_ctx_stack
 
         warnings.warn(
-            "'_app_ctx_stack' is deprecated and will be removed in Flask 2.3.",
+            "'_app_ctx_stack' is deprecated and will be removed in Flask 2.4.",
             DeprecationWarning,
             stacklevel=2,
         )
@@ -62,7 +62,7 @@ def __getattr__(name):
         from .globals import __request_ctx_stack
 
         warnings.warn(
-            "'_request_ctx_stack' is deprecated and will be removed in Flask 2.3.",
+            "'_request_ctx_stack' is deprecated and will be removed in Flask 2.4.",
             DeprecationWarning,
             stacklevel=2,
         )
diff --git a/src/flask/app.py b/src/flask/app.py
index 6d9b1c7e..642d75c1 100644
--- a/src/flask/app.py
+++ b/src/flask/app.py
@@ -1,6 +1,5 @@
 import functools
 import inspect
-import json
 import logging
 import os
 import sys
@@ -75,9 +74,6 @@ if t.TYPE_CHECKING:  # pragma: no cover
     from .testing import FlaskClient
     from .testing import FlaskCliRunner
 
-T_before_first_request = t.TypeVar(
-    "T_before_first_request", bound=ft.BeforeFirstRequestCallable
-)
 T_shell_context_processor = t.TypeVar(
     "T_shell_context_processor", bound=ft.ShellContextProcessorCallable
 )
@@ -274,36 +270,6 @@ class Flask(Scaffold):
     #: :data:`SECRET_KEY` configuration key. Defaults to ``None``.
     secret_key = ConfigAttribute("SECRET_KEY")
 
-    @property
-    def session_cookie_name(self) -> str:
-        """The name of the cookie set by the session interface.
-
-        .. deprecated:: 2.2
-            Will be removed in Flask 2.3. Use ``app.config["SESSION_COOKIE_NAME"]``
-            instead.
-        """
-        import warnings
-
-        warnings.warn(
-            "'session_cookie_name' is deprecated and will be removed in Flask 2.3. Use"
-            " 'SESSION_COOKIE_NAME' in 'app.config' instead.",
-            DeprecationWarning,
-            stacklevel=2,
-        )
-        return self.config["SESSION_COOKIE_NAME"]
-
-    @session_cookie_name.setter
-    def session_cookie_name(self, value: str) -> None:
-        import warnings
-
-        warnings.warn(
-            "'session_cookie_name' is deprecated and will be removed in Flask 2.3. Use"
-            " 'SESSION_COOKIE_NAME' in 'app.config' instead.",
-            DeprecationWarning,
-            stacklevel=2,
-        )
-        self.config["SESSION_COOKIE_NAME"] = value
-
     #: A :class:`~datetime.timedelta` which is used to set the expiration
     #: date of a permanent session.  The default is 31 days which makes a
     #: permanent session survive for roughly one month.
@@ -315,152 +281,6 @@ class Flask(Scaffold):
         "PERMANENT_SESSION_LIFETIME", get_converter=_make_timedelta
     )
 
-    @property
-    def send_file_max_age_default(self) -> t.Optional[timedelta]:
-        """The default value for ``max_age`` for :func:`~flask.send_file`. The default
-        is ``None``, which tells the browser to use conditional requests instead of a
-        timed cache.
-
-        .. deprecated:: 2.2
-            Will be removed in Flask 2.3. Use
-            ``app.config["SEND_FILE_MAX_AGE_DEFAULT"]`` instead.
-
-        .. versionchanged:: 2.0
-            Defaults to ``None`` instead of 12 hours.
-        """
-        import warnings
-
-        warnings.warn(
-            "'send_file_max_age_default' is deprecated and will be removed in Flask"
-            " 2.3. Use 'SEND_FILE_MAX_AGE_DEFAULT' in 'app.config' instead.",
-            DeprecationWarning,
-            stacklevel=2,
-        )
-        return _make_timedelta(self.config["SEND_FILE_MAX_AGE_DEFAULT"])
-
-    @send_file_max_age_default.setter
-    def send_file_max_age_default(self, value: t.Union[int, timedelta, None]) -> None:
-        import warnings
-
-        warnings.warn(
-            "'send_file_max_age_default' is deprecated and will be removed in Flask"
-            " 2.3. Use 'SEND_FILE_MAX_AGE_DEFAULT' in 'app.config' instead.",
-            DeprecationWarning,
-            stacklevel=2,
-        )
-        self.config["SEND_FILE_MAX_AGE_DEFAULT"] = _make_timedelta(value)
-
-    @property
-    def use_x_sendfile(self) -> bool:
-        """Enable this to use the ``X-Sendfile`` feature, assuming the server supports
-        it, from :func:`~flask.send_file`.
-
-        .. deprecated:: 2.2
-            Will be removed in Flask 2.3. Use ``app.config["USE_X_SENDFILE"]`` instead.
-        """
-        import warnings
-
-        warnings.warn(
-            "'use_x_sendfile' is deprecated and will be removed in Flask 2.3. Use"
-            " 'USE_X_SENDFILE' in 'app.config' instead.",
-            DeprecationWarning,
-            stacklevel=2,
-        )
-        return self.config["USE_X_SENDFILE"]
-
-    @use_x_sendfile.setter
-    def use_x_sendfile(self, value: bool) -> None:
-        import warnings
-
-        warnings.warn(
-            "'use_x_sendfile' is deprecated and will be removed in Flask 2.3. Use"
-            " 'USE_X_SENDFILE' in 'app.config' instead.",
-            DeprecationWarning,
-            stacklevel=2,
-        )
-        self.config["USE_X_SENDFILE"] = value
-
-    _json_encoder: t.Union[t.Type[json.JSONEncoder], None] = None
-    _json_decoder: t.Union[t.Type[json.JSONDecoder], None] = None
-
-    @property  # type: ignore[override]
-    def json_encoder(self) -> t.Type[json.JSONEncoder]:
-        """The JSON encoder class to use. Defaults to
-        :class:`~flask.json.JSONEncoder`.
-
-        .. deprecated:: 2.2
-             Will be removed in Flask 2.3. Customize
-             :attr:`json_provider_class` instead.
-
-        .. versionadded:: 0.10
-        """
-        import warnings
-
-        warnings.warn(
-            "'app.json_encoder' is deprecated and will be removed in Flask 2.3."
-            " Customize 'app.json_provider_class' or 'app.json' instead.",
-            DeprecationWarning,
-            stacklevel=2,
-        )
-
-        if self._json_encoder is None:
-            from . import json
-
-            return json.JSONEncoder
-
-        return self._json_encoder
-
-    @json_encoder.setter
-    def json_encoder(self, value: t.Type[json.JSONEncoder]) -> None:
-        import warnings
-
-        warnings.warn(
-            "'app.json_encoder' is deprecated and will be removed in Flask 2.3."
-            " Customize 'app.json_provider_class' or 'app.json' instead.",
-            DeprecationWarning,
-            stacklevel=2,
-        )
-        self._json_encoder = value
-
-    @property  # type: ignore[override]
-    def json_decoder(self) -> t.Type[json.JSONDecoder]:
-        """The JSON decoder class to use. Defaults to
-        :class:`~flask.json.JSONDecoder`.
-
-        .. deprecated:: 2.2
-             Will be removed in Flask 2.3. Customize
-             :attr:`json_provider_class` instead.
-
-        .. versionadded:: 0.10
-        """
-        import warnings
-
-        warnings.warn(
-            "'app.json_decoder' is deprecated and will be removed in Flask 2.3."
-            " Customize 'app.json_provider_class' or 'app.json' instead.",
-            DeprecationWarning,
-            stacklevel=2,
-        )
-
-        if self._json_decoder is None:
-            from . import json
-
-            return json.JSONDecoder
-
-        return self._json_decoder
-
-    @json_decoder.setter
-    def json_decoder(self, value: t.Type[json.JSONDecoder]) -> None:
-        import warnings
-
-        warnings.warn(
-            "'app.json_decoder' is deprecated and will be removed in Flask 2.3."
-            " Customize 'app.json_provider_class' or 'app.json' instead.",
-            DeprecationWarning,
-            stacklevel=2,
-        )
-        self._json_decoder = value
-
     json_provider_class: t.Type[JSONProvider] = DefaultJSONProvider
     """A subclass of :class:`~flask.json.provider.JSONProvider`. An
     instance is created and assigned to :attr:`app.json` when creating
@@ -487,7 +307,6 @@ class Flask(Scaffold):
     #: Default configuration parameters.
     default_config = ImmutableDict(
         {
-            "ENV": None,
             "DEBUG": None,
             "TESTING": False,
             "PROPAGATE_EXCEPTIONS": None,
@@ -509,10 +328,6 @@ class Flask(Scaffold):
             "TRAP_HTTP_EXCEPTIONS": False,
             "EXPLAIN_TEMPLATE_LOADING": False,
             "PREFERRED_URL_SCHEME": "http",
-            "JSON_AS_ASCII": None,
-            "JSON_SORT_KEYS": None,
-            "JSONIFY_PRETTYPRINT_REGULAR": None,
-            "JSONIFY_MIMETYPE": None,
             "TEMPLATES_AUTO_RELOAD": None,
             "MAX_COOKIE_SIZE": 4093,
         }
@@ -625,17 +440,6 @@ class Flask(Scaffold):
             t.Callable[[Exception, str, t.Dict[str, t.Any]], str]
         ] = []
 
-        #: A list of functions that will be called at the beginning of the
-        #: first request to this instance. To register a function, use the
-        #: :meth:`before_first_request` decorator.
-        #:
-        #: .. deprecated:: 2.2
-        #:     Will be removed in Flask 2.3. Run setup code when
-        #:     creating the application instead.
-        #:
-        #: .. versionadded:: 0.8
-        self.before_first_request_funcs: t.List[ft.BeforeFirstRequestCallable] = []
-
         #: A list of functions that are called when the application context
         #: is destroyed.  Since the application context is also torn down
         #: if the request ends this is the place to store code that disconnects
@@ -746,28 +550,6 @@ class Flask(Scaffold):
             return os.path.splitext(os.path.basename(fn))[0]
         return self.import_name
 
-    @property
-    def propagate_exceptions(self) -> bool:
-        """Returns the value of the ``PROPAGATE_EXCEPTIONS`` configuration
-        value in case it's set, otherwise a sensible default is returned.
-
-        .. deprecated:: 2.2
-            Will be removed in Flask 2.3.
-
-        .. versionadded:: 0.7
-        """
-        import warnings
-
-        warnings.warn(
-            "'propagate_exceptions' is deprecated and will be removed in Flask 2.3.",
-            DeprecationWarning,
-            stacklevel=2,
-        )
-        rv = self.config["PROPAGATE_EXCEPTIONS"]
-        if rv is not None:
-            return rv
-        return self.testing or self.debug
-
     @locked_cached_property
     def logger(self) -> logging.Logger:
         """A standard Python :class:`~logging.Logger` for the app, with
@@ -827,7 +609,6 @@ class Flask(Scaffold):
         if instance_relative:
             root_path = self.instance_path
         defaults = dict(self.default_config)
-        defaults["ENV"] = os.environ.get("FLASK_ENV") or "production"
         defaults["DEBUG"] = get_debug_flag()
         return self.config_class(root_path, defaults)
 
@@ -868,42 +649,6 @@ class Flask(Scaffold):
         """
         return open(os.path.join(self.instance_path, resource), mode)
 
-    @property
-    def templates_auto_reload(self) -> bool:
-        """Reload templates when they are changed. Used by
-        :meth:`create_jinja_environment`. It is enabled by default in debug mode.
-
-        .. deprecated:: 2.2
-            Will be removed in Flask 2.3. Use ``app.config["TEMPLATES_AUTO_RELOAD"]``
-            instead.
-
-        .. versionadded:: 1.0
-            This property was added but the underlying config and behavior
-            already existed.
-        """
-        import warnings
-
-        warnings.warn(
-            "'templates_auto_reload' is deprecated and will be removed in Flask 2.3."
-            " Use 'TEMPLATES_AUTO_RELOAD' in 'app.config' instead.",
-            DeprecationWarning,
-            stacklevel=2,
-        )
-        rv = self.config["TEMPLATES_AUTO_RELOAD"]
-        return rv if rv is not None else self.debug
-
-    @templates_auto_reload.setter
-    def templates_auto_reload(self, value: bool) -> None:
-        import warnings
-
-        warnings.warn(
-            "'templates_auto_reload' is deprecated and will be removed in Flask 2.3."
-            " Use 'TEMPLATES_AUTO_RELOAD' in 'app.config' instead.",
-            DeprecationWarning,
-            stacklevel=2,
-        )
-        self.config["TEMPLATES_AUTO_RELOAD"] = value
-
     def create_jinja_environment(self) -> Environment:
         """Create the Jinja environment based on :attr:`jinja_options`
         and the various Jinja-related methods of the app. Changing
@@ -1010,40 +755,6 @@ class Flask(Scaffold):
             rv.update(processor())
         return rv
 
-    @property
-    def env(self) -> str:
-        """What environment the app is running in. This maps to the :data:`ENV` config
-        key.
-
-        **Do not enable development when deploying in production.**
-
-        Default: ``'production'``
-
-        .. deprecated:: 2.2
-            Will be removed in Flask 2.3.
-        """
-        import warnings
-
-        warnings.warn(
-            "'app.env' is deprecated and will be removed in Flask 2.3."
-            " Use 'app.debug' instead.",
-            DeprecationWarning,
-            stacklevel=2,
-        )
-        return self.config["ENV"]
-
-    @env.setter
-    def env(self, value: str) -> None:
-        import warnings
-
-        warnings.warn(
-            "'app.env' is deprecated and will be removed in Flask 2.3."
-            " Use 'app.debug' instead.",
-            DeprecationWarning,
-            stacklevel=2,
-        )
-        self.config["ENV"] = value
-
     @property
     def debug(self) -> bool:
         """Whether debug mode is enabled. When using ``flask run`` to start the
@@ -1144,16 +855,8 @@ class Flask(Scaffold):
         if get_load_dotenv(load_dotenv):
             cli.load_dotenv()
 
-            # if set, let env vars override previous values
-            if "FLASK_ENV" in os.environ:
-                print(
-                    "'FLASK_ENV' is deprecated and will not be used in"
-                    " Flask 2.3. Use 'FLASK_DEBUG' instead.",
-                    file=sys.stderr,
-                )
-                self.config["ENV"] = os.environ.get("FLASK_ENV") or "production"
-                self.debug = get_debug_flag()
-            elif "FLASK_DEBUG" in os.environ:
+            # if set, env var overrides existing value
+            if "FLASK_DEBUG" in os.environ:
                 self.debug = get_debug_flag()
 
         # debug passed to method overrides all other sources
@@ -1479,32 +1182,6 @@ class Flask(Scaffold):
         """
         self.jinja_env.globals[name or f.__name__] = f
 
-    @setupmethod
-    def before_first_request(self, f: T_before_first_request) -> T_before_first_request:
-        """Registers a function to be run before the first request to this
-        instance of the application.
-
-        The function will be called without any arguments and its return
-        value is ignored.
-
-        .. deprecated:: 2.2
-            Will be removed in Flask 2.3. Run setup code when creating
-            the application instead.
-
-        .. versionadded:: 0.8
-        """
-        import warnings
-
-        warnings.warn(
-            "'before_first_request' is deprecated and will be removed"
-            " in Flask 2.3. Run setup code while creating the"
-            " application instead.",
-            DeprecationWarning,
-            stacklevel=2,
-        )
-        self.before_first_request_funcs.append(f)
-        return f
-
     @setupmethod
     def teardown_appcontext(self, f: T_teardown) -> T_teardown:
         """Registers a function to be called when the application
@@ -1682,7 +1359,7 @@ class Flask(Scaffold):
 
         Always sends the :data:`got_request_exception` signal.
 
-        If :attr:`propagate_exceptions` is ``True``, such as in debug
+        If :data:`PROPAGATE_EXCEPTIONS` is ``True``, such as in debug
         mode, the error will be re-raised so that the debugger can
         display it. Otherwise, the original exception is logged, and
         an :exc:`~werkzeug.exceptions.InternalServerError` is returned.
@@ -1805,16 +1482,7 @@ class Flask(Scaffold):
 
         .. versionadded:: 0.7
         """
-        # Run before_first_request functions if this is the thread's first request.
-        # Inlined to avoid a method call on subsequent requests.
-        # This is deprecated, will be removed in Flask 2.3.
-        if not self._got_first_request:
-            with self._before_request_lock:
-                if not self._got_first_request:
-                    for func in self.before_first_request_funcs:
-                        self.ensure_sync(func)()
-
-                    self._got_first_request = True
+        self._got_first_request = True
 
         try:
             request_started.send(self)
diff --git a/src/flask/blueprints.py b/src/flask/blueprints.py
index 4e3fe842..51f72279 100644
--- a/src/flask/blueprints.py
+++ b/src/flask/blueprints.py
@@ -1,4 +1,3 @@
-import json
 import os
 import typing as t
 from collections import defaultdict
@@ -15,9 +14,6 @@ if t.TYPE_CHECKING:  # pragma: no cover
 
 DeferredSetupFunction = t.Callable[["BlueprintSetupState"], t.Callable]
 T_after_request = t.TypeVar("T_after_request", bound=ft.AfterRequestCallable)
-T_before_first_request = t.TypeVar(
-    "T_before_first_request", bound=ft.BeforeFirstRequestCallable
-)
 T_before_request = t.TypeVar("T_before_request", bound=ft.BeforeRequestCallable)
 T_error_handler = t.TypeVar("T_error_handler", bound=ft.ErrorHandlerCallable)
 T_teardown = t.TypeVar("T_teardown", bound=ft.TeardownCallable)
@@ -173,77 +169,6 @@ class Blueprint(Scaffold):
 
     _got_registered_once = False
 
-    _json_encoder: t.Union[t.Type[json.JSONEncoder], None] = None
-    _json_decoder: t.Union[t.Type[json.JSONDecoder], None] = None
-
-    @property
-    def json_encoder(
-        self,
-    ) -> t.Union[t.Type[json.JSONEncoder], None]:
-        """Blueprint-local JSON encoder class to use. Set to ``None`` to use the app's.
-
-        .. deprecated:: 2.2
-             Will be removed in Flask 2.3. Customize
-             :attr:`json_provider_class` instead.
-
-        .. versionadded:: 0.10
-        """
-        import warnings
-
-        warnings.warn(
-            "'bp.json_encoder' is deprecated and will be removed in Flask 2.3."
-            " Customize 'app.json_provider_class' or 'app.json' instead.",
-            DeprecationWarning,
-            stacklevel=2,
-        )
-        return self._json_encoder
-
-    @json_encoder.setter
-    def json_encoder(self, value: t.Union[t.Type[json.JSONEncoder], None]) -> None:
-        import warnings
-
-        warnings.warn(
-            "'bp.json_encoder' is deprecated and will be removed in Flask 2.3."
-            " Customize 'app.json_provider_class' or 'app.json' instead.",
-            DeprecationWarning,
-            stacklevel=2,
-        )
-        self._json_encoder = value
-
-    @property
-    def json_decoder(
-        self,
-    ) -> t.Union[t.Type[json.JSONDecoder], None]:
-        """Blueprint-local JSON decoder class to use. Set to ``None`` to use the app's.
-
-        .. deprecated:: 2.2
-             Will be removed in Flask 2.3. Customize
-             :attr:`json_provider_class` instead.
-
-        .. versionadded:: 0.10
-        """
-        import warnings
-
-        warnings.warn(
-            "'bp.json_decoder' is deprecated and will be removed in Flask 2.3."
-            " Customize 'app.json_provider_class' or 'app.json' instead.",
-            DeprecationWarning,
-            stacklevel=2,
-        )
-        return self._json_decoder
-
-    @json_decoder.setter
-    def json_decoder(self, value: t.Union[t.Type[json.JSONDecoder], None]) -> None:
-        import warnings
-
-        warnings.warn(
-            "'bp.json_decoder' is deprecated and will be removed in Flask 2.3."
-            " Customize 'app.json_provider_class' or 'app.json' instead.",
-            DeprecationWarning,
-            stacklevel=2,
-        )
-        self._json_decoder = value
-
     def __init__(
         self,
         name: str,
@@ -361,6 +286,10 @@ class Blueprint(Scaffold):
         .. versionchanged:: 2.3
             Nested blueprints now correctly apply subdomains.
 
+        .. versionchanged:: 2.1
+            Registering the same blueprint with the same name multiple
+            times is an error.
+
         .. versionchanged:: 2.0.1
             Nested blueprints are registered with their dotted name.
             This allows different blueprints with the same name to be
@@ -371,10 +300,6 @@ class Blueprint(Scaffold):
             name the blueprint is registered with. This allows the same
             blueprint to be registered multiple times with unique names
             for ``url_for``.
-
-        .. versionchanged:: 2.0.1
-            Registering the same blueprint with the same name multiple
-            times is deprecated and will become an error in Flask 2.1.
         """
         name_prefix = options.get("name_prefix", "")
         self_name = options.get("name", self.name)
@@ -634,29 +559,6 @@ class Blueprint(Scaffold):
         )
         return f
 
-    @setupmethod
-    def before_app_first_request(
-        self, f: T_before_first_request
-    ) -> T_before_first_request:
-        """Register a function to run before the first request to the application is
-        handled by the worker. Equivalent to :meth:`.Flask.before_first_request`.
-
-        .. deprecated:: 2.2
-            Will be removed in Flask 2.3. Run setup code when creating
-            the application instead.
-        """
-        import warnings
-
-        warnings.warn(
-            "'before_app_first_request' is deprecated and will be"
-            " removed in Flask 2.3. Use 'record_once' instead to run"
-            " setup code when registering the blueprint.",
-            DeprecationWarning,
-            stacklevel=2,
-        )
-        self.record_once(lambda s: s.app.before_first_request_funcs.append(f))
-        return f
-
     @setupmethod
     def after_app_request(self, f: T_after_request) -> T_after_request:
         """Like :meth:`after_request`, but after every request, not only those handled
diff --git a/src/flask/globals.py b/src/flask/globals.py
index 254da42b..e00a0c10 100644
--- a/src/flask/globals.py
+++ b/src/flask/globals.py
@@ -17,30 +17,17 @@ class _FakeStack:
         self.name = name
         self.cv = cv
 
-    def _warn(self):
+    @property
+    def top(self) -> t.Optional[t.Any]:
         import warnings
 
         warnings.warn(
-            f"'_{self.name}_ctx_stack' is deprecated and will be"
-            " removed in Flask 2.3. Use 'g' to store data, or"
-            f" '{self.name}_ctx' to access the current context.",
+            f"'_{self.name}_ctx_stack' is deprecated and will be removed in Flask 2.4."
+            f" Use 'g' to store data, or '{self.name}_ctx' to access the current"
+            " context.",
             DeprecationWarning,
-            stacklevel=3,
+            stacklevel=2,
         )
-
-    def push(self, obj: t.Any) -> None:
-        self._warn()
-        self.cv.set(obj)
-
-    def pop(self) -> t.Any:
-        self._warn()
-        ctx = self.cv.get(None)
-        self.cv.set(None)
-        return ctx
-
-    @property
-    def top(self) -> t.Optional[t.Any]:
-        self._warn()
         return self.cv.get(None)
 
 
@@ -88,7 +75,7 @@ def __getattr__(name: str) -> t.Any:
         import warnings
 
         warnings.warn(
-            "'_app_ctx_stack' is deprecated and will be removed in Flask 2.3.",
+            "'_app_ctx_stack' is deprecated and will be removed in Flask 2.4.",
             DeprecationWarning,
             stacklevel=2,
         )
@@ -98,7 +85,7 @@ def __getattr__(name: str) -> t.Any:
         import warnings
 
         warnings.warn(
-            "'_request_ctx_stack' is deprecated and will be removed in Flask 2.3.",
+            "'_request_ctx_stack' is deprecated and will be removed in Flask 2.4.",
             DeprecationWarning,
             stacklevel=2,
         )
diff --git a/src/flask/helpers.py b/src/flask/helpers.py
index 3833cb8a..2bf2e628 100644
--- a/src/flask/helpers.py
+++ b/src/flask/helpers.py
@@ -25,45 +25,12 @@ if t.TYPE_CHECKING:  # pragma: no cover
     import typing_extensions as te
 
 
-def get_env() -> str:
-    """Get the environment the app is running in, indicated by the
-    :envvar:`FLASK_ENV` environment variable. The default is
-    ``'production'``.
-
-    .. deprecated:: 2.2
-        Will be removed in Flask 2.3.
-    """
-    import warnings
-
-    warnings.warn(
-        "'FLASK_ENV' and 'get_env' are deprecated and will be removed"
-        " in Flask 2.3. Use 'FLASK_DEBUG' instead.",
-        DeprecationWarning,
-        stacklevel=2,
-    )
-    return os.environ.get("FLASK_ENV") or "production"
-
-
 def get_debug_flag() -> bool:
     """Get whether debug mode should be enabled for the app, indicated by the
     :envvar:`FLASK_DEBUG` environment variable. The default is ``False``.
     """
     val = os.environ.get("FLASK_DEBUG")
-
-    if not val:
-        env = os.environ.get("FLASK_ENV")
-
-        if env is not None:
-            print(
-                "'FLASK_ENV' is deprecated and will not be used in"
-                " Flask 2.3. Use 'FLASK_DEBUG' instead.",
-                file=sys.stderr,
-            )
-            return env == "development"
-
-        return False
-
-    return val.lower() not in {"0", "false", "no"}
+    return bool(val and val.lower() not in {"0", "false", "no"})
 
 
 def get_load_dotenv(default: bool = True) -> bool:
diff --git a/src/flask/json/__init__.py b/src/flask/json/__init__.py
index 65d8829a..f15296fe 100644
--- a/src/flask/json/__init__.py
+++ b/src/flask/json/__init__.py
@@ -3,85 +3,14 @@ from __future__ import annotations
 import json as _json
 import typing as t
 
-from jinja2.utils import htmlsafe_json_dumps as _jinja_htmlsafe_dumps
-
 from ..globals import current_app
 from .provider import _default
 
 if t.TYPE_CHECKING:  # pragma: no cover
-    from ..app import Flask
     from ..wrappers import Response
 
 
-class JSONEncoder(_json.JSONEncoder):
-    """The default JSON encoder. Handles extra types compared to the
-    built-in :class:`json.JSONEncoder`.
-
-    -   :class:`datetime.datetime` and :class:`datetime.date` are
-        serialized to :rfc:`822` strings. This is the same as the HTTP
-        date format.
-    -   :class:`decimal.Decimal` is serialized to a string.
-    -   :class:`uuid.UUID` is serialized to a string.
-    -   :class:`dataclasses.dataclass` is passed to
-        :func:`dataclasses.asdict`.
-    -   :class:`~markupsafe.Markup` (or any object with a ``__html__``
-        method) will call the ``__html__`` method to get a string.
-
-    Assign a subclass of this to :attr:`flask.Flask.json_encoder` or
-    :attr:`flask.Blueprint.json_encoder` to override the default.
-
-    .. deprecated:: 2.2
-        Will be removed in Flask 2.3. Use ``app.json`` instead.
-    """
-
-    def __init__(self, **kwargs) -> None:
-        import warnings
-
-        warnings.warn(
-            "'JSONEncoder' is deprecated and will be removed in"
-            " Flask 2.3. Use 'Flask.json' to provide an alternate"
-            " JSON implementation instead.",
-            DeprecationWarning,
-            stacklevel=3,
-        )
-        super().__init__(**kwargs)
-
-    def default(self, o: t.Any) -> t.Any:
-        """Convert ``o`` to a JSON serializable type. See
-        :meth:`json.JSONEncoder.default`. Python does not support
-        overriding how basic types like ``str`` or ``list`` are
-        serialized, they are handled before this method.
-        """
-        return _default(o)
-
-
-class JSONDecoder(_json.JSONDecoder):
-    """The default JSON decoder.
-
-    This does not change any behavior from the built-in
-    :class:`json.JSONDecoder`.
-
-    Assign a subclass of this to :attr:`flask.Flask.json_decoder` or
-    :attr:`flask.Blueprint.json_decoder` to override the default.
-
-    .. deprecated:: 2.2
-        Will be removed in Flask 2.3. Use ``app.json`` instead.
-    """
-
-    def __init__(self, **kwargs) -> None:
-        import warnings
-
-        warnings.warn(
-            "'JSONDecoder' is deprecated and will be removed in"
-            " Flask 2.3. Use 'Flask.json' to provide an alternate"
-            " JSON implementation instead.",
-            DeprecationWarning,
-            stacklevel=3,
-        )
-        super().__init__(**kwargs)
-
-
-def dumps(obj: t.Any, *, app: Flask | None = None, **kwargs: t.Any) -> str:
+def dumps(obj: t.Any, **kwargs: t.Any) -> str:
     """Serialize data as JSON.
 
     If :data:`~flask.current_app` is available, it will use its
@@ -91,13 +20,13 @@ def dumps(obj: t.Any, *, app: Flask | None = None, **kwargs: t.Any) -> str:
     :param obj: The data to serialize.
     :param kwargs: Arguments passed to the ``dumps`` implementation.
 
+    .. versionchanged:: 2.3
+        The ``app`` parameter was removed.
+
     .. versionchanged:: 2.2
         Calls ``current_app.json.dumps``, allowing an app to override
         the behavior.
 
-    .. versionchanged:: 2.2
-        The ``app`` parameter will be removed in Flask 2.3.
-
     .. versionchanged:: 2.0.2
         :class:`decimal.Decimal` is supported by converting to a string.
 
@@ -108,28 +37,14 @@ def dumps(obj: t.Any, *, app: Flask | None = None, **kwargs: t.Any) -> str:
         ``app`` can be passed directly, rather than requiring an app
         context for configuration.
     """
-    if app is not None:
-        import warnings
-
-        warnings.warn(
-            "The 'app' parameter is deprecated and will be removed in"
-            " Flask 2.3. Call 'app.json.dumps' directly instead.",
-            DeprecationWarning,
-            stacklevel=2,
-        )
-    else:
-        app = current_app
-
-    if app:
-        return app.json.dumps(obj, **kwargs)
+    if current_app:
+        return current_app.json.dumps(obj, **kwargs)
 
     kwargs.setdefault("default", _default)
     return _json.dumps(obj, **kwargs)
 
 
-def dump(
-    obj: t.Any, fp: t.IO[str], *, app: Flask | None = None, **kwargs: t.Any
-) -> None:
+def dump(obj: t.Any, fp: t.IO[str], **kwargs: t.Any) -> None:
     """Serialize data as JSON and write to a file.
 
     If :data:`~flask.current_app` is available, it will use its
@@ -141,37 +56,25 @@ def dump(
         encoding to be valid JSON.
     :param kwargs: Arguments passed to the ``dump`` implementation.
 
+    .. versionchanged:: 2.3
+        The ``app`` parameter was removed.
+
     .. versionchanged:: 2.2
         Calls ``current_app.json.dump``, allowing an app to override
         the behavior.
 
-    .. versionchanged:: 2.2
-        The ``app`` parameter will be removed in Flask 2.3.
-
     .. versionchanged:: 2.0
         Writing to a binary file, and the ``encoding`` argument, will be
         removed in Flask 2.1.
     """
-    if app is not None:
-        import warnings
-
-        warnings.warn(
-            "The 'app' parameter is deprecated and will be removed in"
-            " Flask 2.3. Call 'app.json.dump' directly instead.",
-            DeprecationWarning,
-            stacklevel=2,
-        )
-    else:
-        app = current_app
-
-    if app:
-        app.json.dump(obj, fp, **kwargs)
+    if current_app:
+        current_app.json.dump(obj, fp, **kwargs)
     else:
         kwargs.setdefault("default", _default)
         _json.dump(obj, fp, **kwargs)
 
 
-def loads(s: str | bytes, *, app: Flask | None = None, **kwargs: t.Any) -> t.Any:
+def loads(s: str | bytes, **kwargs: t.Any) -> t.Any:
     """Deserialize data as JSON.
 
     If :data:`~flask.current_app` is available, it will use its
@@ -181,13 +84,13 @@ def loads(s: str | bytes, *, app: Flask | None = None, **kwargs: t.Any) -> t.Any
     :param s: Text or UTF-8 bytes.
     :param kwargs: Arguments passed to the ``loads`` implementation.
 
+    .. versionchanged:: 2.3
+        The ``app`` parameter was removed.
+
     .. versionchanged:: 2.2
         Calls ``current_app.json.loads``, allowing an app to override
         the behavior.
 
-    .. versionchanged:: 2.2
-        The ``app`` parameter will be removed in Flask 2.3.
-
     .. versionchanged:: 2.0
         ``encoding`` will be removed in Flask 2.1. The data must be a
         string or UTF-8 bytes.
@@ -196,25 +99,13 @@ def loads(s: str | bytes, *, app: Flask | None = None, **kwargs: t.Any) -> t.Any
         ``app`` can be passed directly, rather than requiring an app
         context for configuration.
     """
-    if app is not None:
-        import warnings
-
-        warnings.warn(
-            "The 'app' parameter is deprecated and will be removed in"
-            " Flask 2.3. Call 'app.json.loads' directly instead.",
-            DeprecationWarning,
-            stacklevel=2,
-        )
-    else:
-        app = current_app
-
-    if app:
-        return app.json.loads(s, **kwargs)
+    if current_app:
+        return current_app.json.loads(s, **kwargs)
 
     return _json.loads(s, **kwargs)
 
 
-def load(fp: t.IO[t.AnyStr], *, app: Flask | None = None, **kwargs: t.Any) -> t.Any:
+def load(fp: t.IO[t.AnyStr], **kwargs: t.Any) -> t.Any:
     """Deserialize data as JSON read from a file.
 
     If :data:`~flask.current_app` is available, it will use its
@@ -224,6 +115,9 @@ def load(fp: t.IO[t.AnyStr], *, app: Flask | None = None, **kwargs: t.Any) -> t.
     :param fp: A file opened for reading text or UTF-8 bytes.
     :param kwargs: Arguments passed to the ``load`` implementation.
 
+    .. versionchanged:: 2.3
+        The ``app`` parameter was removed.
+
     .. versionchanged:: 2.2
         Calls ``current_app.json.load``, allowing an app to override
         the behavior.
@@ -235,78 +129,12 @@ def load(fp: t.IO[t.AnyStr], *, app: Flask | None = None, **kwargs: t.Any) -> t.
         ``encoding`` will be removed in Flask 2.1. The file must be text
         mode, or binary mode with UTF-8 bytes.
     """
-    if app is not None:
-        import warnings
-
-        warnings.warn(
-            "The 'app' parameter is deprecated and will be removed in"
-            " Flask 2.3. Call 'app.json.load' directly instead.",
-            DeprecationWarning,
-            stacklevel=2,
-        )
-    else:
-        app = current_app
-
-    if app:
-        return app.json.load(fp, **kwargs)
+    if current_app:
+        return current_app.json.load(fp, **kwargs)
 
     return _json.load(fp, **kwargs)
 
 
-def htmlsafe_dumps(obj: t.Any, **kwargs: t.Any) -> str:
-    """Serialize an object to a string of JSON with :func:`dumps`, then
-    replace HTML-unsafe characters with Unicode escapes and mark the
-    result safe with :class:`~markupsafe.Markup`.
-
-    This is available in templates as the ``|tojson`` filter.
-
-    The returned string is safe to render in HTML documents and
-    ``<script>`` tags. The exception is in HTML attributes that are
-    double quoted; either use single quotes or the ``|forceescape``
-    filter.
-
-    .. deprecated:: 2.2
-        Will be removed in Flask 2.3. This is built-in to Jinja now.
-
-    .. versionchanged:: 2.0
-        Uses :func:`jinja2.utils.htmlsafe_json_dumps`. The returned
-        value is marked safe by wrapping in :class:`~markupsafe.Markup`.
-
-    .. versionchanged:: 0.10
-        Single quotes are escaped, making this safe to use in HTML,
-        ``<script>`` tags, and single-quoted attributes without further
-        escaping.
-    """
-    import warnings
-
-    warnings.warn(
-        "'htmlsafe_dumps' is deprecated and will be removed in Flask"
-        " 2.3. Use 'jinja2.utils.htmlsafe_json_dumps' instead.",
-        DeprecationWarning,
-        stacklevel=2,
-    )
-    return _jinja_htmlsafe_dumps(obj, dumps=dumps, **kwargs)
-
-
-def htmlsafe_dump(obj: t.Any, fp: t.IO[str], **kwargs: t.Any) -> None:
-    """Serialize an object to JSON written to a file object, replacing
-    HTML-unsafe characters with Unicode escapes. See
-    :func:`htmlsafe_dumps` and :func:`dumps`.
-
-    .. deprecated:: 2.2
-        Will be removed in Flask 2.3.
-    """
-    import warnings
-
-    warnings.warn(
-        "'htmlsafe_dump' is deprecated and will be removed in Flask"
-        " 2.3. Use 'jinja2.utils.htmlsafe_json_dumps' instead.",
-        DeprecationWarning,
-        stacklevel=2,
-    )
-    fp.write(htmlsafe_dumps(obj, **kwargs))
-
-
 def jsonify(*args: t.Any, **kwargs: t.Any) -> Response:
     """Serialize the given arguments as JSON, and return a
     :class:`~flask.Response` object with the ``application/json``
diff --git a/src/flask/json/provider.py b/src/flask/json/provider.py
index cb6aae80..841e6d4d 100644
--- a/src/flask/json/provider.py
+++ b/src/flask/json/provider.py
@@ -10,8 +10,6 @@ from datetime import date
 
 from werkzeug.http import http_date
 
-from ..globals import request
-
 if t.TYPE_CHECKING:  # pragma: no cover
     from ..app import Flask
     from ..wrappers import Response
@@ -176,57 +174,9 @@ class DefaultJSONProvider(JSONProvider):
         :param obj: The data to serialize.
         :param kwargs: Passed to :func:`json.dumps`.
         """
-        cls = self._app._json_encoder
-        bp = self._app.blueprints.get(request.blueprint) if request else None
-
-        if bp is not None and bp._json_encoder is not None:
-            cls = bp._json_encoder
-
-        if cls is not None:
-            import warnings
-
-            warnings.warn(
-                "Setting 'json_encoder' on the app or a blueprint is"
-                " deprecated and will be removed in Flask 2.3."
-                " Customize 'app.json' instead.",
-                DeprecationWarning,
-            )
-            kwargs.setdefault("cls", cls)
-
-            if "default" not in cls.__dict__:
-                kwargs.setdefault("default", self.default)
-        else:
-            kwargs.setdefault("default", self.default)
-
-        ensure_ascii = self._app.config["JSON_AS_ASCII"]
-        sort_keys = self._app.config["JSON_SORT_KEYS"]
-
-        if ensure_ascii is not None:
-            import warnings
-
-            warnings.warn(
-                "The 'JSON_AS_ASCII' config key is deprecated and will"
-                " be removed in Flask 2.3. Set 'app.json.ensure_ascii'"
-                " instead.",
-                DeprecationWarning,
-            )
-        else:
-            ensure_ascii = self.ensure_ascii
-
-        if sort_keys is not None:
-            import warnings
-
-            warnings.warn(
-                "The 'JSON_SORT_KEYS' config key is deprecated and will"
-                " be removed in Flask 2.3. Set 'app.json.sort_keys'"
-                " instead.",
-                DeprecationWarning,
-            )
-        else:
-            sort_keys = self.sort_keys
-
-        kwargs.setdefault("ensure_ascii", ensure_ascii)
-        kwargs.setdefault("sort_keys", sort_keys)
+        kwargs.setdefault("default", self.default)
+        kwargs.setdefault("ensure_ascii", self.ensure_ascii)
+        kwargs.setdefault("sort_keys", self.sort_keys)
         return json.dumps(obj, **kwargs)
 
     def loads(self, s: str | bytes, **kwargs: t.Any) -> t.Any:
@@ -235,23 +185,6 @@ class DefaultJSONProvider(JSONProvider):
         :param s: Text or UTF-8 bytes.
         :param kwargs: Passed to :func:`json.loads`.
         """
-        cls = self._app._json_decoder
-        bp = self._app.blueprints.get(request.blueprint) if request else None
-
-        if bp is not None and bp._json_decoder is not None:
-            cls = bp._json_decoder
-
-        if cls is not None:
-            import warnings
-
-            warnings.warn(
-                "Setting 'json_decoder' on the app or a blueprint is"
-                " deprecated and will be removed in Flask 2.3."
-                " Customize 'app.json' instead.",
-                DeprecationWarning,
-            )
-            kwargs.setdefault("cls", cls)
-
         return json.loads(s, **kwargs)
 
     def response(self, *args: t.Any, **kwargs: t.Any) -> Response:
@@ -272,39 +205,12 @@ class DefaultJSONProvider(JSONProvider):
         """
         obj = self._prepare_response_obj(args, kwargs)
         dump_args: t.Dict[str, t.Any] = {}
-        pretty = self._app.config["JSONIFY_PRETTYPRINT_REGULAR"]
-        mimetype = self._app.config["JSONIFY_MIMETYPE"]
 
-        if pretty is not None:
-            import warnings
-
-            warnings.warn(
-                "The 'JSONIFY_PRETTYPRINT_REGULAR' config key is"
-                " deprecated and will be removed in Flask 2.3. Set"
-                " 'app.json.compact' instead.",
-                DeprecationWarning,
-            )
-            compact: bool | None = not pretty
-        else:
-            compact = self.compact
-
-        if (compact is None and self._app.debug) or compact is False:
+        if (self.compact is None and self._app.debug) or self.compact is False:
             dump_args.setdefault("indent", 2)
         else:
             dump_args.setdefault("separators", (",", ":"))
 
-        if mimetype is not None:
-            import warnings
-
-            warnings.warn(
-                "The 'JSONIFY_MIMETYPE' config key is deprecated and"
-                " will be removed in Flask 2.3. Set 'app.json.mimetype'"
-                " instead.",
-                DeprecationWarning,
-            )
-        else:
-            mimetype = self.mimetype
-
         return self._app.response_class(
-            f"{self.dumps(obj, **dump_args)}\n", mimetype=mimetype
+            f"{self.dumps(obj, **dump_args)}\n", mimetype=self.mimetype
         )
diff --git a/src/flask/scaffold.py b/src/flask/scaffold.py
index 7277b33a..faa1ce43 100644
--- a/src/flask/scaffold.py
+++ b/src/flask/scaffold.py
@@ -1,5 +1,4 @@
 import importlib.util
-import json
 import os
 import pathlib
 import pkgutil
@@ -74,20 +73,6 @@ class Scaffold:
     _static_folder: t.Optional[str] = None
     _static_url_path: t.Optional[str] = None
 
-    #: JSON encoder class used by :func:`flask.json.dumps`. If a
-    #: blueprint sets this, it will be used instead of the app's value.
-    #:
-    #: .. deprecated:: 2.2
-    #:      Will be removed in Flask 2.3.
-    json_encoder: t.Union[t.Type[json.JSONEncoder], None] = None
-
-    #: JSON decoder class used by :func:`flask.json.loads`. If a
-    #: blueprint sets this, it will be used instead of the app's value.
-    #:
-    #: .. deprecated:: 2.2
-    #:      Will be removed in Flask 2.3.
-    json_decoder: t.Union[t.Type[json.JSONDecoder], None] = None
-
     def __init__(
         self,
         import_name: str,
diff --git a/tests/conftest.py b/tests/conftest.py
index 670acc88..a4168f2e 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -20,7 +20,6 @@ def _standard_os_environ():
     out = (
         (os.environ, "FLASK_ENV_FILE", monkeypatch.notset),
         (os.environ, "FLASK_APP", monkeypatch.notset),
-        (os.environ, "FLASK_ENV", monkeypatch.notset),
         (os.environ, "FLASK_DEBUG", monkeypatch.notset),
         (os.environ, "FLASK_RUN_FROM_CLI", monkeypatch.notset),
         (os.environ, "WERKZEUG_RUN_MAIN", monkeypatch.notset),
diff --git a/tests/test_async.py b/tests/test_async.py
index 38be27c9..f52b0492 100644
--- a/tests/test_async.py
+++ b/tests/test_async.py
@@ -95,7 +95,6 @@ def test_async_error_handler(path, async_app):
 
 
 def test_async_before_after_request():
-    app_first_called = False
     app_before_called = False
     app_after_called = False
     bp_before_called = False
@@ -107,13 +106,6 @@ def test_async_before_after_request():
     def index():
         return ""
 
-    with pytest.deprecated_call():
-
-        @app.before_first_request
-        async def before_first():
-            nonlocal app_first_called
-            app_first_called = True
-
     @app.before_request
     async def before():
         nonlocal app_before_called
@@ -146,7 +138,6 @@ def test_async_before_after_request():
 
     test_client = app.test_client()
     test_client.get("/")
-    assert app_first_called
     assert app_before_called
     assert app_after_called
     test_client.get("/bp/")
diff --git a/tests/test_basic.py b/tests/test_basic.py
index 9aca6679..48d41b1e 100644
--- a/tests/test_basic.py
+++ b/tests/test_basic.py
@@ -1,13 +1,11 @@
 import gc
 import re
-import time
 import uuid
 import warnings
 import weakref
 from datetime import datetime
 from datetime import timezone
 from platform import python_implementation
-from threading import Thread
 
 import pytest
 import werkzeug.serving
@@ -1667,43 +1665,6 @@ def test_no_setup_after_first_request(app, client):
     assert "setup method 'add_url_rule'" in str(exc_info.value)
 
 
-def test_before_first_request_functions(app, client):
-    got = []
-
-    with pytest.deprecated_call():
-
-        @app.before_first_request
-        def foo():
-            got.append(42)
-
-    client.get("/")
-    assert got == [42]
-    client.get("/")
-    assert got == [42]
-    assert app.got_first_request
-
-
-def test_before_first_request_functions_concurrent(app, client):
-    got = []
-
-    with pytest.deprecated_call():
-
-        @app.before_first_request
-        def foo():
-            time.sleep(0.2)
-            got.append(42)
-
-    def get_and_assert():
-        client.get("/")
-        assert got == [42]
-
-    t = Thread(target=get_and_assert)
-    t.start()
-    get_and_assert()
-    t.join()
-    assert app.got_first_request
-
-
 def test_routing_redirect_debugging(monkeypatch, app, client):
     app.config["DEBUG"] = True
 
diff --git a/tests/test_blueprints.py b/tests/test_blueprints.py
index dbe00b97..d46b769b 100644
--- a/tests/test_blueprints.py
+++ b/tests/test_blueprints.py
@@ -722,12 +722,6 @@ def test_app_request_processing(app, client):
     bp = flask.Blueprint("bp", __name__)
     evts = []
 
-    with pytest.deprecated_call():
-
-        @bp.before_app_first_request
-        def before_first_request():
-            evts.append("first")
-
     @bp.before_app_request
     def before_app():
         evts.append("before")
@@ -755,12 +749,12 @@ def test_app_request_processing(app, client):
     # first request
     resp = client.get("/").data
     assert resp == b"request|after"
-    assert evts == ["first", "before", "after", "teardown"]
+    assert evts == ["before", "after", "teardown"]
 
     # second request
     resp = client.get("/").data
     assert resp == b"request|after"
-    assert evts == ["first"] + ["before", "after", "teardown"] * 2
+    assert evts == ["before", "after", "teardown"] * 2
 
 
 def test_app_url_processors(app, client):
diff --git a/tests/test_helpers.py b/tests/test_helpers.py
index 0e6a8856..7e742b16 100644
--- a/tests/test_helpers.py
+++ b/tests/test_helpers.py
@@ -302,24 +302,18 @@ class TestStreaming:
 
 class TestHelpers:
     @pytest.mark.parametrize(
-        "debug, expected_flag, expected_default_flag",
+        ("debug", "expect"),
         [
-            ("", False, False),
-            ("0", False, False),
-            ("False", False, False),
-            ("No", False, False),
-            ("True", True, True),
+            ("", False),
+            ("0", False),
+            ("False", False),
+            ("No", False),
+            ("True", True),
         ],
     )
-    def test_get_debug_flag(
-        self, monkeypatch, debug, expected_flag, expected_default_flag
-    ):
+    def test_get_debug_flag(self, monkeypatch, debug, expect):
         monkeypatch.setenv("FLASK_DEBUG", debug)
-        if expected_flag is None:
-            assert get_debug_flag() is None
-        else:
-            assert get_debug_flag() == expected_flag
-        assert get_debug_flag() == expected_default_flag
+        assert get_debug_flag() == expect
 
     def test_make_response(self):
         app = flask.Flask(__name__)