diff --git a/src/wp-includes/default-filters.php b/src/wp-includes/default-filters.php
index 37cd32d5aa..412251d2f2 100644
--- a/src/wp-includes/default-filters.php
+++ b/src/wp-includes/default-filters.php
@@ -669,4 +669,7 @@ add_action( 'save_post_wp_template_part', 'wp_set_unique_slug_on_create_template
 add_action( 'wp_footer', 'the_block_template_skip_link' );
 add_action( 'setup_theme', 'wp_enable_block_templates' );
 
+// Navigation areas.
+add_action( 'setup_theme', '_register_default_navigation_areas' );
+
 unset( $filter, $action );
diff --git a/src/wp-includes/navigation-areas.php b/src/wp-includes/navigation-areas.php
new file mode 100644
index 0000000000..fd4536199b
--- /dev/null
+++ b/src/wp-includes/navigation-areas.php
@@ -0,0 +1,52 @@
+<?php
+/**
+ * Block navigation areas functions.
+ *
+ * @package WordPress
+ */
+
+/**
+ * Registers the navigation areas supported by the current theme. The expected
+ * shape of the argument is:
+ * array(
+ *     'primary'   => 'Primary',
+ *     'secondary' => 'Secondary',
+ *     'tertiary'  => 'Tertiary',
+ * )
+ *
+ * @since 5.9.0
+ *
+ * @param array $new_areas Supported navigation areas.
+ */
+function register_navigation_areas( $new_areas ) {
+	global $navigation_areas;
+	$navigation_areas = $new_areas;
+}
+
+/**
+ * Register the default navigation areas.
+ *
+ * @since 5.9.0
+ * @access private
+ */
+function _register_default_navigation_areas() {
+	register_navigation_areas(
+		array(
+			'primary'   => _x( 'Primary', 'navigation area' ),
+			'secondary' => _x( 'Secondary', 'navigation area' ),
+			'tertiary'  => _x( 'Tertiary', 'navigation area' ),
+		)
+	);
+}
+
+/**
+ * Returns the available navigation areas.
+ *
+ * @since 5.9.0
+ *
+ * @return array Registered navigation areas.
+ */
+function get_navigation_areas() {
+	global $navigation_areas;
+	return $navigation_areas;
+}
diff --git a/src/wp-includes/rest-api.php b/src/wp-includes/rest-api.php
index ba0f7a08de..517daf513c 100644
--- a/src/wp-includes/rest-api.php
+++ b/src/wp-includes/rest-api.php
@@ -349,6 +349,10 @@ function create_initial_rest_routes() {
 	// Menu Locations.
 	$controller = new WP_REST_Menu_Locations_Controller();
 	$controller->register_routes();
+
+	// Block Navigation Areas
+	$controller = new WP_REST_Block_Navigation_Areas_Controller();
+	$controller->register_routes();
 }
 
 /**
diff --git a/src/wp-includes/rest-api/endpoints/class-wp-rest-block-navigation-areas-controller.php b/src/wp-includes/rest-api/endpoints/class-wp-rest-block-navigation-areas-controller.php
new file mode 100644
index 0000000000..ef515f5970
--- /dev/null
+++ b/src/wp-includes/rest-api/endpoints/class-wp-rest-block-navigation-areas-controller.php
@@ -0,0 +1,310 @@
+<?php
+/**
+ * REST API: WP_REST_Block_Navigation_Areas_Controller class
+ *
+ * @subpackage REST_API
+ * @package WordPress
+ */
+
+/**
+ * Core class used to access block navigation areas via the REST API.
+ *
+ * @since 5.9.0
+ *
+ * @see WP_REST_Controller
+ */
+class WP_REST_Block_Navigation_Areas_Controller extends WP_REST_Controller {
+
+	/**
+	 * Constructor.
+	 *
+	 * @since 5.9.0
+	 */
+	public function __construct() {
+		$this->namespace = 'wp/v2';
+		$this->rest_base = 'block-navigation-areas';
+	}
+
+	/**
+	 * Registers the routes for the objects of the controller.
+	 *
+	 * @since 5.9.0
+	 *
+	 * @see register_rest_route()
+	 */
+	public function register_routes() {
+		register_rest_route(
+			$this->namespace,
+			'/' . $this->rest_base,
+			array(
+				array(
+					'methods'             => WP_REST_Server::READABLE,
+					'callback'            => array( $this, 'get_items' ),
+					'permission_callback' => array( $this, 'get_items_permissions_check' ),
+					'args'                => $this->get_collection_params(),
+				),
+				'schema' => array( $this, 'get_public_item_schema' ),
+			)
+		);
+
+		register_rest_route(
+			$this->namespace,
+			'/' . $this->rest_base . '/(?P<area>[\w-]+)',
+			array(
+				'args'        => array(
+					'area' => array(
+						'description' => __( 'An alphanumeric identifier for the navigation area.' ),
+						'type'        => 'string',
+					),
+				),
+				array(
+					'methods'             => WP_REST_Server::READABLE,
+					'callback'            => array( $this, 'get_item' ),
+					'permission_callback' => array( $this, 'get_item_permissions_check' ),
+					'args'                => array(
+						'context' => $this->get_context_param( array( 'default' => 'view' ) ),
+					),
+				),
+				array(
+					'methods'             => WP_REST_Server::EDITABLE,
+					'callback'            => array( $this, 'update_item' ),
+					'permission_callback' => array( $this, 'update_item_permissions_check' ),
+					'args'                => $this->get_endpoint_args_for_item_schema( WP_REST_Server::EDITABLE ),
+				),
+				'allow_batch' => array( 'v1' => true ),
+				'schema'      => array( $this, 'get_public_item_schema' ),
+			)
+		);
+	}
+
+	/**
+	 * Checks whether a given request has permission to read navigation areas.
+	 *
+	 * @since 5.9.0
+	 *
+	 * @param WP_REST_Request $request Full details about the request.
+	 * @return WP_Error|bool True if the request has read access, WP_Error object otherwise.
+	 */
+	public function get_items_permissions_check( $request ) {
+		if ( ! current_user_can( 'edit_theme_options' ) ) {
+			return new WP_Error(
+				'rest_cannot_view',
+				__( 'Sorry, you are not allowed to view navigation areas.' ),
+				array( 'status' => rest_authorization_required_code() )
+			);
+		}
+
+		return true;
+	}
+
+	/**
+	 * Retrieves all navigation areas, depending on user context.
+	 *
+	 * @since 5.9.0
+	 *
+	 * @param WP_REST_Request $request Full details about the request.
+	 * @return WP_Error|WP_REST_Response Response object on success, or WP_Error object on failure.
+	 */
+	public function get_items( $request ) {
+		$data = array();
+		foreach ( get_navigation_areas() as $name => $description ) {
+			$area   = $this->get_navigation_area_object( $name );
+			$area   = $this->prepare_item_for_response( $area, $request );
+			$data[] = $this->prepare_response_for_collection( $area );
+		}
+		return rest_ensure_response( $data );
+	}
+
+	/**
+	 * Checks if a given request has access to read a navigation area.
+	 *
+	 * @since 5.9.0
+	 *
+	 * @param WP_REST_Request $request Full details about the request.
+	 * @return WP_Error|bool True if the request has read access for the item, WP_Error object otherwise.
+	 */
+	public function get_item_permissions_check( $request ) {
+		if ( ! current_user_can( 'edit_theme_options' ) ) {
+			return new WP_Error(
+				'rest_cannot_view',
+				__( 'Sorry, you are not allowed to view navigation areas.' ),
+				array( 'status' => rest_authorization_required_code() )
+			);
+		}
+		if ( ! array_key_exists( $request['area'], get_navigation_areas() ) ) {
+			return new WP_Error( 'rest_navigation_area_invalid', __( 'Invalid navigation area.' ), array( 'status' => 404 ) );
+		}
+
+		return true;
+	}
+
+	/**
+	 * Checks if a request has access to update the specified term.
+	 *
+	 * @since 5.9.0
+	 *
+	 * @param WP_REST_Request $request Full details about the request.
+	 * @return bool|WP_Error True if the request has access to update the item, false or WP_Error object otherwise.
+	 */
+	public function update_item_permissions_check( $request ) {
+		return $this->get_item_permissions_check( $request );
+	}
+
+	/**
+	 * Retrieves a specific navigation area.
+	 *
+	 * @since 5.9.0
+	 *
+	 * @param WP_REST_Request $request Full details about the request.
+	 * @return WP_Error|WP_REST_Response Response object on success, or WP_Error object on failure.
+	 */
+	public function get_item( $request ) {
+		$name = $request['area'];
+		$area = $this->get_navigation_area_object( $name );
+		$data = $this->prepare_item_for_response( $area, $request );
+
+		return rest_ensure_response( $data );
+	}
+
+	/**
+	 * Updates a specific navigation area.
+	 *
+	 * @since 5.9.0
+	 *
+	 * @param WP_REST_Request $request Full details about the request.
+	 * @return WP_Error|WP_REST_Response Response object on success, or WP_Error object on failure.
+	 */
+	public function update_item( $request ) {
+		$name = $request['area'];
+
+		$mapping          = get_option( 'fse_navigation_areas', array() );
+		$mapping[ $name ] = $request['navigation'];
+		update_option( 'fse_navigation_areas', $mapping );
+
+		$area = $this->get_navigation_area_object( $name );
+		$data = $this->prepare_item_for_response( $area, $request );
+		return rest_ensure_response( $data );
+	}
+
+	/**
+	 * Converts navigation area name to a convenient object that this endpoint can reason about.
+	 *
+	 * @since 5.9.0
+	 *
+	 * @param string $name Navigation area name.
+	 * @return stdClass An object representation of the navigation area.
+	 */
+	protected function get_navigation_area_object( $name ) {
+		$available_areas   = get_navigation_areas();
+		$mapping           = get_option( 'fse_navigation_areas', array() );
+		$area              = new stdClass();
+		$area->name        = $name;
+		$area->navigation  = ! empty( $mapping[ $name ] ) ? $mapping[ $name ] : null;
+		$area->description = $available_areas[ $name ];
+		return $area;
+	}
+
+	/**
+	 * Prepares a navigation area object for serialization.
+	 *
+	 * @since 5.9.0
+	 *
+	 * @param stdClass        $area    Post status data.
+	 * @param WP_REST_Request $request Full details about the request.
+	 * @return WP_REST_Response Post status data.
+	 */
+	public function prepare_item_for_response( $area, $request ) {
+		$areas      = get_navigation_areas();
+		$navigation = ( isset( $areas[ $area->name ] ) ) ? $area->navigation : 0;
+
+		$fields = $this->get_fields_for_response( $request );
+		$data   = array();
+
+		if ( rest_is_field_included( 'name', $fields ) ) {
+			$data['name'] = $area->name;
+		}
+
+		if ( rest_is_field_included( 'description', $fields ) ) {
+			$data['description'] = $area->description;
+		}
+
+		if ( rest_is_field_included( 'navigation', $fields ) ) {
+			$data['navigation'] = (int) $navigation;
+		}
+
+		$context = ! empty( $request['context'] ) ? $request['context'] : 'view';
+		$data    = $this->add_additional_fields_to_object( $data, $request );
+		$data    = $this->filter_response_by_context( $data, $context );
+
+		$response = rest_ensure_response( $data );
+
+		/**
+		 * Filters a navigation area returned from the REST API.
+		 *
+		 * @since 5.9.0
+		 *
+		 * Allows modification of the navigation area data right before it is
+		 * returned.
+		 *
+		 * @param WP_REST_Response $response The response object.
+		 * @param object           $area     The original status object.
+		 * @param WP_REST_Request  $request  Request used to generate the response.
+		 */
+		return apply_filters( 'rest_prepare_navigation_area', $response, $area, $request );
+	}
+
+	/**
+	 * Retrieves the navigation area's schema, conforming to JSON Schema.
+	 *
+	 * @since 5.9.0
+	 *
+	 * @return array Item schema data.
+	 */
+	public function get_item_schema() {
+		if ( $this->schema ) {
+			return $this->schema;
+		}
+
+		$this->schema = array(
+			'$schema'    => 'http://json-schema.org/draft-04/schema#',
+			'title'      => 'navigation-area',
+			'type'       => 'object',
+			'properties' => array(
+				'name'        => array(
+					'description' => __( 'The name of the navigation area.' ),
+					'type'        => 'string',
+					'context'     => array( 'embed', 'view', 'edit' ),
+					'readonly'    => true,
+				),
+				'description' => array(
+					'description' => __( 'The description of the navigation area.' ),
+					'type'        => 'string',
+					'context'     => array( 'embed', 'view', 'edit' ),
+					'readonly'    => true,
+				),
+				'navigation'  => array(
+					'description' => __( 'The ID of the assigned navigation.' ),
+					'type'        => 'integer',
+					'context'     => array( 'embed', 'view', 'edit' ),
+					'readonly'    => true,
+				),
+			),
+		);
+
+		return $this->add_additional_fields_schema( $this->schema );
+	}
+
+	/**
+	 * Retrieves the query params for collections.
+	 *
+	 * @since 5.9.0
+	 *
+	 * @return array Collection parameters.
+	 */
+	public function get_collection_params() {
+		return array(
+			'context' => $this->get_context_param( array( 'default' => 'view' ) ),
+		);
+	}
+
+}
diff --git a/src/wp-settings.php b/src/wp-settings.php
index 1293c82208..0a55449bfc 100644
--- a/src/wp-settings.php
+++ b/src/wp-settings.php
@@ -244,8 +244,9 @@ require ABSPATH . WPINC . '/class-wp-http-requests-hooks.php';
 require ABSPATH . WPINC . '/widgets.php';
 require ABSPATH . WPINC . '/class-wp-widget.php';
 require ABSPATH . WPINC . '/class-wp-widget-factory.php';
-require ABSPATH . WPINC . '/nav-menu.php';
 require ABSPATH . WPINC . '/nav-menu-template.php';
+require ABSPATH . WPINC . '/nav-menu.php';
+require ABSPATH . WPINC . '/navigation-areas.php';
 require ABSPATH . WPINC . '/admin-bar.php';
 require ABSPATH . WPINC . '/class-wp-application-passwords.php';
 require ABSPATH . WPINC . '/rest-api.php';
@@ -275,6 +276,7 @@ require ABSPATH . WPINC . '/rest-api/endpoints/class-wp-rest-settings-controller
 require ABSPATH . WPINC . '/rest-api/endpoints/class-wp-rest-themes-controller.php';
 require ABSPATH . WPINC . '/rest-api/endpoints/class-wp-rest-plugins-controller.php';
 require ABSPATH . WPINC . '/rest-api/endpoints/class-wp-rest-block-directory-controller.php';
+require ABSPATH . WPINC . '/rest-api/endpoints/class-wp-rest-block-navigation-areas-controller.php';
 require ABSPATH . WPINC . '/rest-api/endpoints/class-wp-rest-pattern-directory-controller.php';
 require ABSPATH . WPINC . '/rest-api/endpoints/class-wp-rest-application-passwords-controller.php';
 require ABSPATH . WPINC . '/rest-api/endpoints/class-wp-rest-site-health-controller.php';
diff --git a/tests/phpunit/tests/rest-api/rest-schema-setup.php b/tests/phpunit/tests/rest-api/rest-schema-setup.php
index 1ed1d89611..500f6acdd0 100644
--- a/tests/phpunit/tests/rest-api/rest-schema-setup.php
+++ b/tests/phpunit/tests/rest-api/rest-schema-setup.php
@@ -171,6 +171,8 @@ class WP_Test_REST_Schema_Initialization extends WP_Test_REST_TestCase {
 			'/wp/v2/navigation/(?P<parent>[\d]+)/autosaves/(?P<id>[\d]+)',
 			'/wp/v2/navigation/(?P<parent>[\d]+)/revisions',
 			'/wp/v2/navigation/(?P<parent>[\d]+)/revisions/(?P<id>[\d]+)',
+			'/wp/v2/block-navigation-areas',
+			'/wp/v2/block-navigation-areas/(?P<area>[\w-]+)',
 			'/wp-site-health/v1',
 			'/wp-site-health/v1/tests/background-updates',
 			'/wp-site-health/v1/tests/loopback-requests',
diff --git a/tests/phpunit/tests/rest-api/wpRestBlockNavigationAreasController.php b/tests/phpunit/tests/rest-api/wpRestBlockNavigationAreasController.php
new file mode 100644
index 0000000000..b35fc75ad8
--- /dev/null
+++ b/tests/phpunit/tests/rest-api/wpRestBlockNavigationAreasController.php
@@ -0,0 +1,136 @@
+<?php
+/**
+ * Unit tests covering WP_REST_Block_Navigation_Areas_Controller functionality.
+ *
+ * @package WordPress
+ * @subpackage REST_API
+ * @group restapi
+ * @since 5.9.0
+ */
+class Tests_REST_WpRestBlockNavigationAreasController extends WP_Test_REST_Controller_Testcase {
+
+	const OPTION = 'fse_navigation_areas';
+
+	/**
+	 * @var int Administrator user ID
+	 */
+	protected static $admin_id;
+
+	/**
+	 * @var array Contains mapping
+	 */
+	protected static $old_mapping;
+
+	public static function wpSetUpBeforeClass( WP_UnitTest_Factory $factory ) {
+		self::$admin_id = $factory->user->create(
+			array(
+				'role' => 'administrator',
+			)
+		);
+
+		static::$old_mapping = get_option( static::OPTION, array() );
+	}
+
+	public static function wpTearDownAfterClass() {
+		self::delete_user( self::$admin_id );
+		update_option( static::OPTION, static::$old_mapping );
+	}
+
+	public function test_get_items() {
+		wp_set_current_user( static::$admin_id );
+		$request = new WP_REST_Request( 'GET', '/wp/v2/block-navigation-areas' );
+
+		$response = rest_get_server()->dispatch( $request );
+		$this->assertSame( 200, $response->get_status() );
+		$data = $response->get_data();
+		$this->assertIsArray( $data );
+		$navigation_areas = get_navigation_areas();
+		$expected_data    = array();
+		foreach ( $navigation_areas as $name => $navigation_area ) {
+			$expected_data[] = array(
+				'name'        => $name,
+				'description' => $navigation_area,
+				'navigation'  => 0,
+			);
+		}
+		$this->assertSameSets( $expected_data, $data );
+	}
+
+	public function test_register_routes() {
+		wp_set_current_user( static::$admin_id );
+		$routes = rest_get_server()->get_routes();
+		$this->assertArrayHasKey( '/wp/v2/block-navigation-areas', $routes );
+		$this->assertArrayHasKey( '/wp/v2/block-navigation-areas/(?P<area>[\\w-]+)', $routes );
+	}
+
+	public function test_context_param() {
+		wp_set_current_user( static::$admin_id );
+		$request  = new WP_REST_Request( Requests::OPTIONS, '/wp/v2/block-navigation-areas' );
+		$response = rest_get_server()->dispatch( $request );
+		$this->assertSame( 200, $response->get_status() );
+		$data = $response->get_data();
+
+		$this->assertSame( 'view', $data['endpoints'][0]['args']['context']['default'] );
+		$this->assertSame( array( 'view', 'embed', 'edit' ), $data['endpoints'][0]['args']['context']['enum'] );
+	}
+
+	public function test_get_item() {
+		wp_set_current_user( static::$admin_id );
+		$navigation_area = array_rand( get_navigation_areas(), 1 );
+
+		$this->assertIsString( $navigation_area );
+		$this->assertNotEmpty( $navigation_area );
+
+		$route    = sprintf( '/wp/v2/block-navigation-areas/%s', urlencode( $navigation_area ) );
+		$request  = new WP_REST_Request( 'GET', $route );
+		$response = rest_get_server()->dispatch( $request );
+		$this->assertSame( 200, $response->get_status() );
+		$data = $response->get_data();
+		$this->assertIsArray( $data );
+		$this->assertArrayHasKey( 'name', $data );
+		$this->assertSame( $navigation_area, $data['name'] );
+	}
+
+	public function test_create_item() {
+		// We cannot create new navigation areas using the current block navigation areas API,
+		// so the test should be marked as passed.
+		$this->markTestSkipped();
+	}
+
+	public function test_update_item() {
+		wp_set_current_user( static::$admin_id );
+		$navigation_area = array_rand( get_navigation_areas(), 1 );
+		$route           = sprintf( '/wp/v2/block-navigation-areas/%s', urlencode( $navigation_area ) );
+		$request         = new WP_REST_Request( Requests::POST, $route );
+
+		$updated_navigation_area = array(
+			'name'        => $navigation_area,
+			'description' => 'Test Description',
+		);
+
+		$request->set_param( 'navigation', $updated_navigation_area );
+		$response = rest_get_server()->dispatch( $request );
+		$this->assertSame( 200, $response->get_status() );
+		$new_mapping = get_option( static::OPTION, array() );
+		$this->assertSame( $new_mapping[ $navigation_area ], $updated_navigation_area );
+	}
+
+	public function test_delete_item() {
+		// We cannot delete navigation areas using the current block navigation areas API,
+		// so the test should be marked as passed.
+		$this->markTestSkipped();
+	}
+
+	public function test_prepare_item() {
+		// The current block navigation areas API doesn't implement any custom prepare_item logic
+		// so there is nothing to test.
+		$this->markTestSkipped();
+	}
+
+	public function test_get_item_schema() {
+		// The current block navigation areas API doesn't implement any custom item schema
+		// so there is nothing to test.
+		$this->markTestSkipped();
+	}
+}
+
diff --git a/tests/qunit/fixtures/wp-api-generated.js b/tests/qunit/fixtures/wp-api-generated.js
index eb5633ba25..3e4b8f80ad 100644
--- a/tests/qunit/fixtures/wp-api-generated.js
+++ b/tests/qunit/fixtures/wp-api-generated.js
@@ -10367,6 +10367,93 @@ mockedApiResponse.Schema = {
                     }
                 }
             ]
+        },
+        "/wp/v2/block-navigation-areas": {
+            "namespace": "wp/v2",
+            "methods": [
+                "GET"
+            ],
+            "endpoints": [
+                {
+                    "methods": [
+                        "GET"
+                    ],
+                    "args": {
+                        "context": {
+                            "description": "Scope under which the request is made; determines fields present in response.",
+                            "type": "string",
+                            "enum": [
+                                "view",
+                                "embed",
+                                "edit"
+                            ],
+                            "default": "view",
+                            "required": false
+                        }
+                    }
+                }
+            ],
+            "_links": {
+                "self": [
+                    {
+                        "href": "http://example.org/index.php?rest_route=/wp/v2/block-navigation-areas"
+                    }
+                ]
+            }
+        },
+        "/wp/v2/block-navigation-areas/(?P<area>[\\w-]+)": {
+            "namespace": "wp/v2",
+            "methods": [
+                "GET",
+                "POST",
+                "PUT",
+                "PATCH"
+            ],
+            "endpoints": [
+                {
+                    "methods": [
+                        "GET"
+                    ],
+                    "allow_batch": {
+                        "v1": true
+                    },
+                    "args": {
+                        "area": {
+                            "description": "An alphanumeric identifier for the navigation area.",
+                            "type": "string",
+                            "required": false
+                        },
+                        "context": {
+                            "description": "Scope under which the request is made; determines fields present in response.",
+                            "type": "string",
+                            "enum": [
+                                "view",
+                                "embed",
+                                "edit"
+                            ],
+                            "default": "view",
+                            "required": false
+                        }
+                    }
+                },
+                {
+                    "methods": [
+                        "POST",
+                        "PUT",
+                        "PATCH"
+                    ],
+                    "allow_batch": {
+                        "v1": true
+                    },
+                    "args": {
+                        "area": {
+                            "description": "An alphanumeric identifier for the navigation area.",
+                            "type": "string",
+                            "required": false
+                        }
+                    }
+                }
+            ]
         }
     },
     "site_logo": 0,