diff --git a/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/mongo/MongoProperties.java b/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/mongo/MongoProperties.java
index e757a845f8b..3c891da93b2 100644
--- a/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/mongo/MongoProperties.java
+++ b/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/mongo/MongoProperties.java
@@ -59,8 +59,7 @@ public class MongoProperties {
 	private Integer port = null;
 
 	/**
-	 * Mongo database URI. Cannot be set with host, port, credentials and replica set
-	 * name.
+	 * Mongo database URI. Overrides host, port, username, password, and database.
 	 */
 	private String uri;
 
diff --git a/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/mongo/MongoPropertiesClientSettingsBuilderCustomizer.java b/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/mongo/MongoPropertiesClientSettingsBuilderCustomizer.java
index 2326e00af35..f677fc315c7 100644
--- a/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/mongo/MongoPropertiesClientSettingsBuilderCustomizer.java
+++ b/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/mongo/MongoPropertiesClientSettingsBuilderCustomizer.java
@@ -25,7 +25,6 @@ import com.mongodb.ServerAddress;
 
 import org.springframework.core.Ordered;
 import org.springframework.core.env.Environment;
-import org.springframework.util.Assert;
 
 /**
  * A {@link MongoClientSettingsBuilderCustomizer} that applies properties from a
@@ -49,20 +48,12 @@ public class MongoPropertiesClientSettingsBuilderCustomizer implements MongoClie
 
 	@Override
 	public void customize(MongoClientSettings.Builder settingsBuilder) {
-		validateConfiguration();
 		applyUuidRepresentation(settingsBuilder);
 		applyHostAndPort(settingsBuilder);
 		applyCredentials(settingsBuilder);
 		applyReplicaSet(settingsBuilder);
 	}
 
-	private void validateConfiguration() {
-		if (hasCustomAddress() || hasCustomCredentials() || hasReplicaSet()) {
-			Assert.state(this.properties.getUri() == null,
-					"Invalid mongo configuration, either uri or host/port/credentials/replicaSet must be specified");
-		}
-	}
-
 	private void applyUuidRepresentation(MongoClientSettings.Builder settingsBuilder) {
 		settingsBuilder.uuidRepresentation(this.properties.getUuidRepresentation());
 	}
@@ -72,20 +63,23 @@ public class MongoPropertiesClientSettingsBuilderCustomizer implements MongoClie
 			settings.applyConnectionString(new ConnectionString("mongodb://localhost:" + getEmbeddedPort()));
 			return;
 		}
-
-		if (hasCustomAddress()) {
+		if (this.properties.getUri() != null) {
+			settings.applyConnectionString(new ConnectionString(this.properties.getUri()));
+			return;
+		}
+		if (this.properties.getHost() != null || this.properties.getPort() != null) {
 			String host = getOrDefault(this.properties.getHost(), "localhost");
 			int port = getOrDefault(this.properties.getPort(), MongoProperties.DEFAULT_PORT);
 			ServerAddress serverAddress = new ServerAddress(host, port);
 			settings.applyToClusterSettings((cluster) -> cluster.hosts(Collections.singletonList(serverAddress)));
 			return;
 		}
-
-		settings.applyConnectionString(new ConnectionString(this.properties.determineUri()));
+		settings.applyConnectionString(new ConnectionString(MongoProperties.DEFAULT_URI));
 	}
 
 	private void applyCredentials(MongoClientSettings.Builder builder) {
-		if (hasCustomCredentials()) {
+		if (this.properties.getUri() == null && this.properties.getUsername() != null
+				&& this.properties.getPassword() != null) {
 			String database = (this.properties.getAuthenticationDatabase() != null)
 					? this.properties.getAuthenticationDatabase() : this.properties.getMongoClientDatabase();
 			builder.credential((MongoCredential.createCredential(this.properties.getUsername(), database,
@@ -94,7 +88,7 @@ public class MongoPropertiesClientSettingsBuilderCustomizer implements MongoClie
 	}
 
 	private void applyReplicaSet(MongoClientSettings.Builder builder) {
-		if (hasReplicaSet()) {
+		if (this.properties.getReplicaSetName() != null) {
 			builder.applyToClusterSettings(
 					(cluster) -> cluster.requiredReplicaSetName(this.properties.getReplicaSetName()));
 		}
@@ -114,18 +108,6 @@ public class MongoPropertiesClientSettingsBuilderCustomizer implements MongoClie
 		return null;
 	}
 
-	private boolean hasCustomCredentials() {
-		return this.properties.getUsername() != null && this.properties.getPassword() != null;
-	}
-
-	private boolean hasCustomAddress() {
-		return this.properties.getHost() != null || this.properties.getPort() != null;
-	}
-
-	private boolean hasReplicaSet() {
-		return this.properties.getReplicaSetName() != null;
-	}
-
 	@Override
 	public int getOrder() {
 		return this.order;
diff --git a/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/mongo/MongoPropertiesClientSettingsBuilderCustomizerTests.java b/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/mongo/MongoPropertiesClientSettingsBuilderCustomizerTests.java
index 77130fd5b6b..f877d8e332d 100644
--- a/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/mongo/MongoPropertiesClientSettingsBuilderCustomizerTests.java
+++ b/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/mongo/MongoPropertiesClientSettingsBuilderCustomizerTests.java
@@ -27,7 +27,6 @@ import org.junit.jupiter.api.Test;
 import org.springframework.mock.env.MockEnvironment;
 
 import static org.assertj.core.api.Assertions.assertThat;
-import static org.assertj.core.api.Assertions.assertThatIllegalStateException;
 
 /**
  * Tests for {@link MongoPropertiesClientSettingsBuilderCustomizer}.
@@ -153,29 +152,34 @@ class MongoPropertiesClientSettingsBuilderCustomizerTests {
 	}
 
 	@Test
-	void uriCannotBeSetWithCredentials() {
+	void uriOverridesUsernameAndPassword() {
 		this.properties.setUri("mongodb://127.0.0.1:1234/mydb");
 		this.properties.setUsername("user");
 		this.properties.setPassword("secret".toCharArray());
-		assertThatIllegalStateException().isThrownBy(this::customizeSettings).withMessageContaining(
-				"Invalid mongo configuration, either uri or host/port/credentials/replicaSet must be specified");
+		MongoClientSettings settings = customizeSettings();
+		assertThat(settings.getCredential()).isNull();
 	}
 
 	@Test
-	void uriCannotBeSetWithReplicaSetName() {
-		this.properties.setUri("mongodb://127.0.0.1:1234/mydb");
-		this.properties.setReplicaSetName("test");
-		assertThatIllegalStateException().isThrownBy(this::customizeSettings).withMessageContaining(
-				"Invalid mongo configuration, either uri or host/port/credentials/replicaSet must be specified");
+	void uriOverridesDatabase() {
+		this.properties.setUri("mongodb://secret:password@127.0.0.1:1234/mydb");
+		this.properties.setDatabase("test");
+		MongoClientSettings settings = customizeSettings();
+		List<ServerAddress> allAddresses = getAllAddresses(settings);
+		assertThat(allAddresses).hasSize(1);
+		assertServerAddress(allAddresses.get(0), "127.0.0.1", 1234);
+		assertThat(settings.getCredential().getSource()).isEqualTo("mydb");
 	}
 
 	@Test
-	void uriCannotBeSetWithHostPort() {
+	void uriOverridesHostAndPort() {
 		this.properties.setUri("mongodb://127.0.0.1:1234/mydb");
 		this.properties.setHost("localhost");
 		this.properties.setPort(4567);
-		assertThatIllegalStateException().isThrownBy(this::customizeSettings).withMessageContaining(
-				"Invalid mongo configuration, either uri or host/port/credentials/replicaSet must be specified");
+		MongoClientSettings settings = customizeSettings();
+		List<ServerAddress> addresses = getAllAddresses(settings);
+		assertThat(addresses.get(0).getHost()).isEqualTo("127.0.0.1");
+		assertThat(addresses.get(0).getPort()).isEqualTo(1234);
 	}
 
 	@Test