diff --git a/src/wp-includes/capabilities.php b/src/wp-includes/capabilities.php
index d06887a2bb..1e55d55f53 100644
--- a/src/wp-includes/capabilities.php
+++ b/src/wp-includes/capabilities.php
@@ -1030,6 +1030,30 @@ function add_role( $role, $display_name, $capabilities = array() ) {
 	return wp_roles()->add_role( $role, $display_name, $capabilities );
 }
 
+/**
+ * Updates an existing role. Creates a new role if it doesn't exist.
+ *
+ * Modifies the display name and/or capabilities for an existing role.
+ * If the role does not exist then a new role is created.
+ *
+ * The capabilities are defined in the following format: `array( 'read' => true )`.
+ * To explicitly deny the role a capability, set the value for that capability to false.
+ *
+ * @since 6.1.0
+ *
+ * @param string      $role         Role name.
+ * @param string|null $display_name Optional. Role display name. If null, the display name
+ *                                  is not modified. Default null.
+ * @param bool[]|null $capabilities Optional. List of capabilities keyed by the capability name,
+ *                                  e.g. `array( 'edit_posts' => true, 'delete_posts' => false )`.
+ *                                  If null, don't alter capabilities for the existing role and make
+ *                                  empty capabilities for the new one. Default null.
+ * @return WP_Role|void WP_Role object, if the role is updated.
+ */
+function update_role( $role, $display_name = null, $capabilities = null ) {
+	return wp_roles()->update_role( $role, $display_name, $capabilities );
+}
+
 /**
  * Removes a role, if it exists.
  *
diff --git a/src/wp-includes/class-wp-roles.php b/src/wp-includes/class-wp-roles.php
index f224250fa2..d5eb97ef38 100644
--- a/src/wp-includes/class-wp-roles.php
+++ b/src/wp-includes/class-wp-roles.php
@@ -172,6 +172,76 @@ class WP_Roles {
 		return $this->role_objects[ $role ];
 	}
 
+	/**
+	 * Updates an existing role. Creates a new role if it doesn't exist.
+	 *
+	 * Modifies the display name and/or capabilities for an existing role.
+	 * If the role does not exist then a new role is created.
+	 *
+	 * The capabilities are defined in the following format: `array( 'read' => true )`.
+	 * To explicitly deny the role a capability, set the value for that capability to false.
+	 *
+	 * @since 6.1.0
+	 *
+	 * @param string      $role         Role name.
+	 * @param string|null $display_name Optional. Role display name. If null, the display name
+	 *                                  is not modified. Default null.
+	 * @param bool[]|null $capabilities Optional. List of capabilities keyed by the capability name,
+	 *                                  e.g. `array( 'edit_posts' => true, 'delete_posts' => false )`.
+	 *                                  If null, don't alter capabilities for the existing role and make
+	 *                                  empty capabilities for the new one. Default null.
+	 * @return WP_Role|void WP_Role object, if the role is updated.
+	 */
+	public function update_role( $role, $display_name = null, $capabilities = null ) {
+		if ( ! is_string( $role ) || '' === trim( $role ) ) {
+			return;
+		}
+
+		if ( null !== $display_name && ( ! is_string( $display_name ) || '' === trim( $display_name ) ) ) {
+			return;
+		}
+
+		if ( null !== $capabilities && ! is_array( $capabilities ) ) {
+			return;
+		}
+
+		if ( null === $display_name && null === $capabilities ) {
+			if ( isset( $this->role_objects[ $role ] ) ) {
+				return $this->role_objects[ $role ];
+			}
+			return;
+		}
+
+		if ( null === $display_name ) {
+			if ( ! isset( $this->role_objects[ $role ] ) ) {
+				return;
+			}
+
+			$display_name = $this->roles[ $role ]['name'];
+		}
+
+		if ( null === $capabilities ) {
+			if ( isset( $this->role_objects[ $role ] ) ) {
+				$capabilities = $this->role_objects[ $role ]->capabilities;
+			} else {
+				$capabilities = array();
+			}
+		}
+
+		if ( isset( $this->roles[ $role ] ) ) {
+			if ( null === $capabilities ) {
+				$capabilities = $this->role_objects[ $role ]->capabilities;
+			}
+
+			unset( $this->role_objects[ $role ] );
+			unset( $this->role_names[ $role ] );
+			unset( $this->roles[ $role ] );
+		}
+
+		// The roles database option will be updated in ::add_role().
+		return $this->add_role( $role, $display_name, $capabilities );
+	}
+
 	/**
 	 * Removes a role by name.
 	 *
diff --git a/tests/phpunit/tests/user/capabilities.php b/tests/phpunit/tests/user/capabilities.php
index c7e836f6e5..3e49adc39d 100644
--- a/tests/phpunit/tests/user/capabilities.php
+++ b/tests/phpunit/tests/user/capabilities.php
@@ -998,6 +998,461 @@ class Tests_User_Capabilities extends WP_UnitTestCase {
 		$this->assertFalse( $wp_roles->is_role( $role_name ) );
 	}
 
+	/**
+	 * @dataProvider data_update_role_unhappy_paths
+	 *
+	 * @ticket 54572
+	 *
+	 * @covers WP_Roles::update_role
+	 * @covers ::update_role
+	 *
+	 * @param mixed $role         The role to update.
+	 * @param mixed $display_name The display name for the role.
+	 * @param mixed $capabilities The capabilities for the role.
+	 */
+	public function test_update_role_unhappy_paths( $role, $display_name, $capabilities ) {
+		global $wp_roles;
+
+		// Create role if it does not exist.
+		$role_name     = 'janitor';
+		$expected_caps = array(
+			'edit_posts' => true,
+			'edit_pages' => true,
+			'level_0'    => true,
+			'level_1'    => true,
+			'level_2'    => true,
+		);
+		add_role( $role_name, 'Janitor', $expected_caps );
+		$this->flush_roles();
+
+		$this->assertTrue(
+			$wp_roles->is_role( $role_name ),
+			"The $role_name role was not created"
+		);
+
+		$this->assertNotInstanceOf(
+			'WP_Role',
+			update_role( $role, $display_name, $capabilities ),
+			"The $role_name role was updated"
+		);
+
+		// Clean up.
+		remove_role( $role_name );
+		$this->flush_roles();
+		$this->assertFalse(
+			$wp_roles->is_role( $role_name ),
+			"The $role_name role was not removed"
+		);
+	}
+
+	/**
+	 * Data provider.
+	 *
+	 * @return array
+	 */
+	public function data_update_role_unhappy_paths() {
+		return array(
+			'true as the role'                       => array(
+				'role'         => true,
+				'display_name' => 'Janitor',
+				'capabilities' => array(
+					'level_1' => true,
+				),
+			),
+			'false as the role'                      => array(
+				'role'         => false,
+				'display_name' => 'Janitor',
+				'capabilities' => array(
+					'level_1' => true,
+				),
+			),
+			'null as the role'                       => array(
+				'role'         => null,
+				'display_name' => 'Janitor',
+				'capabilities' => array(
+					'level_1' => true,
+				),
+			),
+			'(int) 1 as the role'                    => array(
+				'role'         => 1,
+				'display_name' => 'Janitor',
+				'capabilities' => array(
+					'level_1' => true,
+				),
+			),
+			'(float) 1.0 as the role'                => array(
+				'role'         => 1.0,
+				'display_name' => 'Janitor',
+				'capabilities' => array(
+					'level_1' => true,
+				),
+			),
+			'(int) 0 as the role'                    => array(
+				'role'         => 0,
+				'display_name' => 'Janitor',
+				'capabilities' => array(
+					'level_1' => true,
+				),
+			),
+			'(float) 0.0 as the role'                => array(
+				'role'         => 0.0,
+				'display_name' => 'Janitor',
+				'capabilities' => array(
+					'level_1' => true,
+				),
+			),
+			'an empty string as the role'            => array(
+				'role'         => '',
+				'display_name' => 'Janitor',
+				'capabilities' => array(
+					'level_1' => true,
+				),
+			),
+			'a string with only a space as the role' => array(
+				'role'         => ' ',
+				'display_name' => 'Janitor',
+				'capabilities' => array(
+					'level_1' => true,
+				),
+			),
+			'an empty array as the role'             => array(
+				'role'         => array(),
+				'display_name' => 'Janitor',
+				'capabilities' => array(
+					'level_1' => true,
+				),
+			),
+			'a non-empty array as the role'          => array(
+				'role'         => array( 'janitor' ),
+				'display_name' => 'Janitor',
+				'capabilities' => array(
+					'level_1' => true,
+				),
+			),
+			'an object as the role'                  => array(
+				'role'         => (object) array( 'janitor' ),
+				'display_name' => 'Janitor',
+				'capabilities' => array(
+					'level_1' => true,
+				),
+			),
+			'true as the display name'               => array(
+				'role'         => 'janitor',
+				'display_name' => true,
+				'capabilities' => array(
+					'level_1' => true,
+				),
+			),
+			'false as the display name'              => array(
+				'role'         => 'janitor',
+				'display_name' => false,
+				'capabilities' => array(
+					'level_1' => true,
+				),
+			),
+			'(int) 1 as the display name'            => array(
+				'role'         => 'janitor',
+				'display_name' => 1,
+				'capabilities' => array(
+					'level_1' => true,
+				),
+			),
+			'(float) 1.0 as the display name'        => array(
+				'role'         => 'janitor',
+				'display_name' => 1.0,
+				'capabilities' => array(
+					'level_1' => true,
+				),
+			),
+			'(int) 0 as the display name'            => array(
+				'role'         => 'janitor',
+				'display_name' => 0,
+				'capabilities' => array(
+					'level_1' => true,
+				),
+			),
+			'(float) 0.0 as the display name'        => array(
+				'role'         => 'janitor',
+				'display_name' => 0.0,
+				'capabilities' => array(
+					'level_1' => true,
+				),
+			),
+			'an empty string as the display name'    => array(
+				'role'         => 'janitor',
+				'display_name' => '',
+				'capabilities' => array(
+					'level_1' => true,
+				),
+			),
+			'a string with only a space as the display name' => array(
+				'role'         => 'janitor',
+				'display_name' => ' ',
+				'capabilities' => array(
+					'level_1' => true,
+				),
+			),
+			'an empty array as the display name'     => array(
+				'role'         => 'janitor',
+				'display_name' => array(),
+				'capabilities' => array(
+					'level_1' => true,
+				),
+			),
+			'a non-empty array as the display name'  => array(
+				'role'         => 'janitor',
+				'display_name' => array( 'Janitor' ),
+				'capabilities' => array(
+					'level_1' => true,
+				),
+			),
+			'an object as the display name'          => array(
+				'role'         => 'janitor',
+				'display_name' => (object) array( 'Janitor' ),
+				'capabilities' => array(
+					'level_1' => true,
+				),
+			),
+			'true as the capabilities'               => array(
+				'role'         => 'janitor',
+				'display_name' => 'Janitor',
+				'capabilities' => true,
+			),
+			'false as the capabilities'              => array(
+				'role'         => (object) array( 'janitor' ),
+				'display_name' => 'Janitor',
+				'capabilities' => false,
+			),
+			'(int) 1 as the capabilities'            => array(
+				'role'         => 'janitor',
+				'display_name' => 'Janitor',
+				'capabilities' => 1,
+			),
+			'(float) 1.0 as the capabilities'        => array(
+				'role'         => 'janitor',
+				'display_name' => 'Janitor',
+				'capabilities' => 1.0,
+			),
+			'(int) 0 as the capabilities'            => array(
+				'role'         => 'janitor',
+				'display_name' => 'Janitor',
+				'capabilities' => 0,
+			),
+			'(float) 0.0 as the capabilities'        => array(
+				'role'         => 'janitor',
+				'display_name' => 'Janitor',
+				'capabilities' => 0.0,
+			),
+			'an empty string as the capabilities'    => array(
+				'role'         => 'janitor',
+				'display_name' => 'Janitor',
+				'capabilities' => '',
+			),
+			'a string with only a space as the capabilities' => array(
+				'role'         => 'janitor',
+				'display_name' => 'Janitor',
+				'capabilities' => ' ',
+			),
+			'an object as the capabilities'          => array(
+				'role'         => 'janitor',
+				'display_name' => 'Janitor',
+				'capabilities' => (object) array( 'level_1' => true ),
+			),
+		);
+	}
+
+	/**
+	 * @ticket 54572
+	 *
+	 * @covers WP_Roles::update_role
+	 * @covers ::update_role
+	 */
+	public function test_update_role_should_create_a_role_if_it_does_not_exist() {
+		global $wp_roles;
+
+		// Create role if it does not exist.
+		$role_name     = 'janitor';
+		$expected_caps = array(
+			'edit_posts' => true,
+			'edit_pages' => true,
+			'level_0'    => true,
+			'level_1'    => true,
+			'level_2'    => true,
+		);
+		update_role( $role_name, 'Janitor', $expected_caps );
+		$this->flush_roles();
+		$this->assertTrue( $wp_roles->is_role( $role_name ) );
+	}
+
+	/**
+	 * @ticket 54572
+	 *
+	 * @covers WP_Roles::update_role
+	 * @covers ::update_role
+	 */
+	public function test_update_role_should_change_the_display_name_of_a_role() {
+		global $wp_roles;
+		$role_name = 'janitor';
+
+		add_role( $role_name, 'Janitor', array( 'level_1' => true ) );
+		$this->flush_roles();
+
+		$expected_display_name = 'Janitor Executive';
+		update_role( $role_name, $expected_display_name );
+		$this->flush_roles();
+
+		$this->assertSame(
+			$expected_display_name,
+			$wp_roles->roles[ $role_name ]['name'],
+			'The expected display name was not correct'
+		);
+		$this->assertSame(
+			array( 'level_1' => true ),
+			$wp_roles->roles[ $role_name ]['capabilities'],
+			'The expected capabilities were not correct'
+		);
+
+		// Clean up.
+		remove_role( $role_name );
+		$this->flush_roles();
+		$this->assertFalse(
+			$wp_roles->is_role( $role_name ),
+			"The $role_name role was not removed"
+		);
+	}
+
+	/**
+	 * @dataProvider data_update_role_should_change_the_capabilities_of_a_role
+	 *
+	 * @ticket 54572
+	 *
+	 * @covers WP_Roles::update_role
+	 * @covers ::update_role
+	 *
+	 * @param array $capabilities An array of capabilities.
+	 */
+	public function test_update_role_should_change_the_capabilities_of_a_role( $capabilities ) {
+		global $wp_roles;
+		$role_name = 'janitor';
+
+		add_role( $role_name, 'Janitor', array( 'level_1' => true ) );
+		$this->flush_roles();
+
+		update_role( $role_name, null, $capabilities );
+		$this->flush_roles();
+
+		$this->assertSame(
+			'Janitor',
+			$wp_roles->roles[ $role_name ]['name'],
+			'The display name was changed'
+		);
+		$this->assertSame(
+			$capabilities,
+			$wp_roles->roles[ $role_name ]['capabilities'],
+			'The expected capabilities were not correct'
+		);
+
+		// Clean up.
+		remove_role( $role_name );
+		$this->flush_roles();
+		$this->assertFalse(
+			$wp_roles->is_role( $role_name ),
+			"The $role_name role was not removed"
+		);
+	}
+
+	/**
+	 * Data provider.
+	 *
+	 * @return array
+	 */
+	public function data_update_role_should_change_the_capabilities_of_a_role() {
+		return array(
+			'an empty array'           => array( 'capabilities' => array() ),
+			'an array of capabilities' => array( 'capabilities' => array( 'level_2' => true ) ),
+		);
+	}
+
+	/**
+	 * @ticket 54572
+	 *
+	 * @covers WP_Roles::update_role
+	 * @covers ::update_role
+	 */
+	public function test_update_role_should_change_display_name_and_capabilities_of_role() {
+		global $wp_roles;
+		$role_name = 'janitor';
+
+		add_role( $role_name, 'Janitor', array( 'level_1' => true ) );
+		$this->flush_roles();
+
+		$expected_display_name = 'Janitor Manager';
+		$new_expected_caps     = array(
+			'level_3' => true,
+			'level_4' => true,
+		);
+		update_role( $role_name, $expected_display_name, $new_expected_caps );
+		$this->flush_roles();
+
+		$this->assertSame(
+			$expected_display_name,
+			$wp_roles->roles[ $role_name ]['name'],
+			'The expected display name was not correct'
+		);
+
+		$this->assertSame(
+			$new_expected_caps,
+			$wp_roles->roles[ $role_name ]['capabilities'],
+			'The expected capabilities were not correct'
+		);
+
+		// Clean up.
+		remove_role( $role_name );
+		$this->flush_roles();
+		$this->assertFalse(
+			$wp_roles->is_role( $role_name ),
+			"The $role_name role was not removed"
+		);
+	}
+
+	/**
+	 * @ticket 54572
+	 *
+	 * @covers WP_Roles::update_role
+	 * @covers ::update_role
+	 */
+	public function test_update_role_should_change_capabilities_of_a_user() {
+		global $wp_roles;
+		$role_name = 'janitor';
+
+		add_role( $role_name, 'Janitor', array( 'level_1' => true ) );
+		$this->flush_roles();
+
+		// Assign a user to the role.
+		$id = self::factory()->user->create( array( 'role' => $role_name ) );
+
+		// Update empty capabilities.
+		update_role( $role_name, null, array( 'level_2' => true ) );
+		$this->flush_roles();
+
+		$this->assertTrue(
+			user_can( $id, 'level_2' ),
+			'The user does not have level_2 capabilities'
+		);
+		$this->assertFalse(
+			user_can( $id, 'level_1' ),
+			'The user has level_1 capabilities'
+		);
+
+		// Clean up.
+		remove_role( $role_name );
+		$this->flush_roles();
+		$this->assertFalse(
+			$wp_roles->is_role( $role_name ),
+			"The $role_name role was not removed"
+		);
+	}
+
 	/**
 	 * Change the capabilites associated with a role and make sure the change
 	 * is reflected in has_cap().