diff --git a/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/data/mongo/MongoDatabaseFactoryConfiguration.java b/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/data/mongo/MongoDatabaseFactoryConfiguration.java
index 0c1915d12e15..2ab6fad362b2 100644
--- a/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/data/mongo/MongoDatabaseFactoryConfiguration.java
+++ b/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/data/mongo/MongoDatabaseFactoryConfiguration.java
@@ -35,6 +35,7 @@
  * @author Stephane Nicoll
  * @author Moritz Halbritter
  * @author Phillip Webb
+ * @author Scott Frederick
  */
 @Configuration(proxyBeanMethods = false)
 @ConditionalOnMissingBean(MongoDatabaseFactory.class)
@@ -44,7 +45,11 @@ class MongoDatabaseFactoryConfiguration {
 	@Bean
 	MongoDatabaseFactorySupport<?> mongoDatabaseFactory(MongoClient mongoClient, MongoProperties properties,
 			MongoConnectionDetails connectionDetails) {
-		return new SimpleMongoClientDatabaseFactory(mongoClient, connectionDetails.getConnectionString().getDatabase());
+		String database = properties.getDatabase();
+		if (database == null) {
+			database = connectionDetails.getConnectionString().getDatabase();
+		}
+		return new SimpleMongoClientDatabaseFactory(mongoClient, database);
 	}
 
 }
diff --git a/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/data/mongo/MongoReactiveDataAutoConfiguration.java b/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/data/mongo/MongoReactiveDataAutoConfiguration.java
index b2480e747e54..ecdf179b611c 100644
--- a/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/data/mongo/MongoReactiveDataAutoConfiguration.java
+++ b/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/data/mongo/MongoReactiveDataAutoConfiguration.java
@@ -67,6 +67,7 @@
  * @author Moritz Halbritter
  * @author Andy Wilkinson
  * @author Phillip Webb
+ * @author Scott Frederick
  * @since 2.0.0
  */
 @AutoConfiguration(after = MongoReactiveAutoConfiguration.class)
@@ -84,9 +85,13 @@ public class MongoReactiveDataAutoConfiguration {
 
 	@Bean
 	@ConditionalOnMissingBean(ReactiveMongoDatabaseFactory.class)
-	public SimpleReactiveMongoDatabaseFactory reactiveMongoDatabaseFactory(MongoClient mongo) {
-		return new SimpleReactiveMongoDatabaseFactory(mongo,
-				this.connectionDetails.getConnectionString().getDatabase());
+	public SimpleReactiveMongoDatabaseFactory reactiveMongoDatabaseFactory(MongoClient mongo,
+			MongoProperties properties) {
+		String database = properties.getDatabase();
+		if (database == null) {
+			database = this.connectionDetails.getConnectionString().getDatabase();
+		}
+		return new SimpleReactiveMongoDatabaseFactory(mongo, database);
 	}
 
 	@Bean
diff --git a/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/data/mongo/MongoDataAutoConfigurationTests.java b/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/data/mongo/MongoDataAutoConfigurationTests.java
index 50941bf7f353..590fb36bdf1f 100644
--- a/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/data/mongo/MongoDataAutoConfigurationTests.java
+++ b/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/data/mongo/MongoDataAutoConfigurationTests.java
@@ -64,6 +64,7 @@
  * @author Moritz Halbritter
  * @author Andy Wilkinson
  * @author Phillip Webb
+ * @author Scott Frederick
  */
 class MongoDataAutoConfigurationTests {
 
@@ -226,6 +227,64 @@ void autoConfiguresIfUserProvidesMongoDatabaseFactoryButNoClient() {
 			.run((context) -> assertThat(context).hasSingleBean(MongoTemplate.class));
 	}
 
+	@Test
+	void databaseHasDefault() {
+		this.contextRunner.run((context) -> {
+			MongoDatabaseFactory factory = context.getBean(MongoDatabaseFactory.class);
+			assertThat(factory).isInstanceOf(SimpleMongoClientDatabaseFactory.class);
+			assertThat(factory.getMongoDatabase().getName()).isEqualTo("test");
+		});
+	}
+
+	@Test
+	void databasePropertyIsUsed() {
+		this.contextRunner.withPropertyValues("spring.data.mongodb.database=mydb").run((context) -> {
+			MongoDatabaseFactory factory = context.getBean(MongoDatabaseFactory.class);
+			assertThat(factory).isInstanceOf(SimpleMongoClientDatabaseFactory.class);
+			assertThat(factory.getMongoDatabase().getName()).isEqualTo("mydb");
+		});
+	}
+
+	@Test
+	void databaseInUriPropertyIsUsed() {
+		this.contextRunner.withPropertyValues("spring.data.mongodb.uri=mongodb://mongo.example.com/mydb")
+			.run((context) -> {
+				MongoDatabaseFactory factory = context.getBean(MongoDatabaseFactory.class);
+				assertThat(factory).isInstanceOf(SimpleMongoClientDatabaseFactory.class);
+				assertThat(factory.getMongoDatabase().getName()).isEqualTo("mydb");
+			});
+	}
+
+	@Test
+	void databasePropertyOverridesUriProperty() {
+		this.contextRunner
+			.withPropertyValues("spring.data.mongodb.uri=mongodb://mongo.example.com/notused",
+					"spring.data.mongodb.database=mydb")
+			.run((context) -> {
+				MongoDatabaseFactory factory = context.getBean(MongoDatabaseFactory.class);
+				assertThat(factory).isInstanceOf(SimpleMongoClientDatabaseFactory.class);
+				assertThat(factory.getMongoDatabase().getName()).isEqualTo("mydb");
+			});
+	}
+
+	@Test
+	void databasePropertyIsUsedWhenNoDatabaseInUri() {
+		this.contextRunner
+			.withPropertyValues("spring.data.mongodb.uri=mongodb://mongo.example.com/",
+					"spring.data.mongodb.database=mydb")
+			.run((context) -> {
+				MongoDatabaseFactory factory = context.getBean(MongoDatabaseFactory.class);
+				assertThat(factory).isInstanceOf(SimpleMongoClientDatabaseFactory.class);
+				assertThat(factory.getMongoDatabase().getName()).isEqualTo("mydb");
+			});
+	}
+
+	@Test
+	void contextFailsWhenDatabaseNotSet() {
+		this.contextRunner.withPropertyValues("spring.data.mongodb.uri=mongodb://mongo.example.com/")
+			.run((context) -> assertThat(context).getFailure().hasMessageContaining("Database name must not be empty"));
+	}
+
 	@Test
 	void definesPropertiesBasedConnectionDetailsByDefault() {
 		this.contextRunner.run((context) -> assertThat(context).hasSingleBean(PropertiesMongoConnectionDetails.class));
diff --git a/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/data/mongo/MongoReactiveDataAutoConfigurationTests.java b/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/data/mongo/MongoReactiveDataAutoConfigurationTests.java
index ee11af22c99e..df9a5f264ee2 100644
--- a/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/data/mongo/MongoReactiveDataAutoConfigurationTests.java
+++ b/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/data/mongo/MongoReactiveDataAutoConfigurationTests.java
@@ -29,6 +29,7 @@
 import org.springframework.context.annotation.Configuration;
 import org.springframework.data.mongodb.ReactiveMongoDatabaseFactory;
 import org.springframework.data.mongodb.core.ReactiveMongoTemplate;
+import org.springframework.data.mongodb.core.SimpleReactiveMongoDatabaseFactory;
 import org.springframework.data.mongodb.gridfs.ReactiveGridFsTemplate;
 import org.springframework.test.util.ReflectionTestUtils;
 
@@ -42,6 +43,7 @@
  * @author Moritz Halbritter
  * @author Andy Wilkinson
  * @author Phillip Webb
+ * @author Scott Frederick
  */
 class MongoReactiveDataAutoConfigurationTests {
 
@@ -90,6 +92,64 @@ void backsOffIfMongoClientBeanIsNotPresent() {
 		runner.run((context) -> assertThat(context).doesNotHaveBean(MongoReactiveDataAutoConfiguration.class));
 	}
 
+	@Test
+	void databaseHasDefault() {
+		this.contextRunner.run((context) -> {
+			ReactiveMongoDatabaseFactory factory = context.getBean(ReactiveMongoDatabaseFactory.class);
+			assertThat(factory).isInstanceOf(SimpleReactiveMongoDatabaseFactory.class);
+			assertThat(factory.getMongoDatabase().block().getName()).isEqualTo("test");
+		});
+	}
+
+	@Test
+	void databasePropertyIsUsed() {
+		this.contextRunner.withPropertyValues("spring.data.mongodb.database=mydb").run((context) -> {
+			ReactiveMongoDatabaseFactory factory = context.getBean(ReactiveMongoDatabaseFactory.class);
+			assertThat(factory).isInstanceOf(SimpleReactiveMongoDatabaseFactory.class);
+			assertThat(factory.getMongoDatabase().block().getName()).isEqualTo("mydb");
+		});
+	}
+
+	@Test
+	void databaseInUriPropertyIsUsed() {
+		this.contextRunner.withPropertyValues("spring.data.mongodb.uri=mongodb://mongo.example.com/mydb")
+			.run((context) -> {
+				ReactiveMongoDatabaseFactory factory = context.getBean(ReactiveMongoDatabaseFactory.class);
+				assertThat(factory).isInstanceOf(SimpleReactiveMongoDatabaseFactory.class);
+				assertThat(factory.getMongoDatabase().block().getName()).isEqualTo("mydb");
+			});
+	}
+
+	@Test
+	void databasePropertyOverridesUriProperty() {
+		this.contextRunner
+			.withPropertyValues("spring.data.mongodb.uri=mongodb://mongo.example.com/notused",
+					"spring.data.mongodb.database=mydb")
+			.run((context) -> {
+				ReactiveMongoDatabaseFactory factory = context.getBean(ReactiveMongoDatabaseFactory.class);
+				assertThat(factory).isInstanceOf(SimpleReactiveMongoDatabaseFactory.class);
+				assertThat(factory.getMongoDatabase().block().getName()).isEqualTo("mydb");
+			});
+	}
+
+	@Test
+	void databasePropertyIsUsedWhenNoDatabaseInUri() {
+		this.contextRunner
+			.withPropertyValues("spring.data.mongodb.uri=mongodb://mongo.example.com/",
+					"spring.data.mongodb.database=mydb")
+			.run((context) -> {
+				ReactiveMongoDatabaseFactory factory = context.getBean(ReactiveMongoDatabaseFactory.class);
+				assertThat(factory).isInstanceOf(SimpleReactiveMongoDatabaseFactory.class);
+				assertThat(factory.getMongoDatabase().block().getName()).isEqualTo("mydb");
+			});
+	}
+
+	@Test
+	void contextFailsWhenDatabaseNotSet() {
+		this.contextRunner.withPropertyValues("spring.data.mongodb.uri=mongodb://mongo.example.com/")
+			.run((context) -> assertThat(context).getFailure().hasMessageContaining("Database name must not be empty"));
+	}
+
 	private String grisFsTemplateDatabaseName(AssertableApplicationContext context) {
 		assertThat(context).hasSingleBean(ReactiveGridFsTemplate.class);
 		ReactiveGridFsTemplate template = context.getBean(ReactiveGridFsTemplate.class);