diff --git a/src/wp-includes/entity-actions.php b/src/wp-includes/entity-actions.php
index 13ec78bc03e33..426fd1d30943a 100644
--- a/src/wp-includes/entity-actions.php
+++ b/src/wp-includes/entity-actions.php
@@ -189,13 +189,16 @@ function _wp_add_entity_action_modules_to_editor_script( $scripts = null ) {
 }
 
 /**
- * Preloads the actions of the post type the post editor edits.
+ * Preloads the actions of the post types the editors list.
  *
- * The actions menu of the post editor reads them from the `wp/v2/entity-actions`
- * route as it loads, see `useEntityActions()` in
- * packages/editor/src/dataviews/entity-actions-loader.ts. The path must match the
- * request of the `getEntityActionsConfig` core data resolver, see
- * packages/core-data/src/resolvers.js.
+ * The editors read them from the `/wp/v2/entity-actions` route as they load,
+ * see `useEntityActions()` in
+ * packages/editor/src/dataviews/entity-actions-loader.ts in Gutenberg. The
+ * post editor reads those of the edited post in its actions menu. The site
+ * editor reads those of the edited post, if any, and of the post types of the
+ * screen it opens on, whose lists show the actions of their items. A path must
+ * match the request of the `getEntityActionsConfig` core data resolver, see
+ * packages/core-data/src/resolvers.js in Gutenberg.
  *
  * @since 7.2.0
  *
@@ -204,11 +207,24 @@ function _wp_add_entity_action_modules_to_editor_script( $scripts = null ) {
  * @return array Filtered preload paths.
  */
 function _wp_preload_entity_actions( $paths, $context ) {
+	$post_types = array();
 	if ( 'core/edit-post' === $context->name && isset( $context->post ) ) {
+		$post_types[] = $context->post->post_type;
+	} elseif ( 'core/edit-site' === $context->name ) {
+		if ( isset( $context->post ) ) {
+			$post_types[] = $context->post->post_type;
+		}
+		$post_types = array_merge( $post_types, _wp_get_site_editor_screen_post_types() );
+	}
+
+	foreach ( array_unique( $post_types ) as $post_type ) {
+		if ( ! post_type_exists( $post_type ) ) {
+			continue;
+		}
 		$paths[] = add_query_arg(
 			array(
 				'kind' => 'postType',
-				'name' => $context->post->post_type,
+				'name' => $post_type,
 			),
 			'/wp/v2/entity-actions'
 		);
diff --git a/src/wp-includes/entity-fields.php b/src/wp-includes/entity-fields.php
index 91a0547557a3e..779a32f7fe3f2 100644
--- a/src/wp-includes/entity-fields.php
+++ b/src/wp-includes/entity-fields.php
@@ -288,8 +288,8 @@ function _wp_get_post_type_fields_preload_paths( $post_types ) {
 }
 
 /**
- * Returns the post types whose fields the screen of the site editor being
- * loaded lists, from its `p` query arg.
+ * Returns the post types whose items the screen of the site editor being
+ * loaded lists or edits, from its `p` query arg.
  *
  * The screens are the routes in
  * packages/edit-site/src/components/site-editor-routes in Gutenberg: the
@@ -323,16 +323,13 @@ function _wp_get_site_editor_screen_post_types() {
 }
 
 /**
- * Preloads the fields of the post types the site editor lists.
+ * Preloads the fields of the post types the editors list.
  *
- * The site editor reads them from the `/wp/v2/entity-fields` route before it
- * can list the post fields, see `useFields` in
- * packages/editor/src/dataviews/fields-loader/index.ts in Gutenberg: those of
- * the edited post, if any, and of the post types of the screen it opens on.
- *
- * The post editor is left untouched: it only reads the fields in the
- * DataForm-based inspector, an experiment of the Gutenberg plugin which
- * preloads them on its own.
+ * The editors read them from the `/wp/v2/entity-fields` route, see `useFields`
+ * in packages/editor/src/dataviews/fields-loader/index.ts in Gutenberg. The
+ * post editor reads those of the edited post in the post summary of its
+ * inspector. The site editor reads those of the edited post, if any, and of
+ * the post types of the screen it opens on.
  *
  * @since 7.2.0
  * @access private
@@ -342,15 +339,15 @@ function _wp_get_site_editor_screen_post_types() {
  * @return array Filtered preload paths.
  */
 function _wp_preload_entity_fields( $paths, $context ) {
-	if ( 'core/edit-site' !== $context->name ) {
-		return $paths;
-	}
-
 	$post_types = array();
-	if ( isset( $context->post ) ) {
+	if ( 'core/edit-post' === $context->name && isset( $context->post ) ) {
 		$post_types[] = $context->post->post_type;
+	} elseif ( 'core/edit-site' === $context->name ) {
+		if ( isset( $context->post ) ) {
+			$post_types[] = $context->post->post_type;
+		}
+		$post_types = array_merge( $post_types, _wp_get_site_editor_screen_post_types() );
 	}
-	$post_types = array_merge( $post_types, _wp_get_site_editor_screen_post_types() );
 
 	return array_merge(
 		$paths,
diff --git a/tests/phpunit/tests/entity-actions.php b/tests/phpunit/tests/entity-actions.php
index 4625df3f4a205..5643906778bc2 100644
--- a/tests/phpunit/tests/entity-actions.php
+++ b/tests/phpunit/tests/entity-actions.php
@@ -42,6 +42,7 @@ public function set_up() {
 	 * the actions WordPress registers back.
 	 */
 	public function tear_down() {
+		unset( $_GET['p'] );
 		self::reset_registry();
 
 		parent::tear_down();
@@ -428,15 +429,83 @@ public function test_the_preloaded_actions_path_serves_the_actions() {
 	}
 
 	/**
-	 * Only the post editor preloads the actions: the other editors have no
-	 * post type of their own.
+	 * The site editor preloads the actions of the post types its screen lists,
+	 * from the `p` query arg.
+	 *
+	 * @ticket 66343
+	 *
+	 * @dataProvider data_site_editor_screens
+	 *
+	 * @param string   $path       The `p` query arg.
+	 * @param string[] $post_types The post types whose actions are preloaded.
+	 */
+	public function test_the_site_editor_preloads_the_actions_of_its_screen( $path, $post_types ) {
+		$_GET['p'] = $path;
+		$context   = new WP_Block_Editor_Context( array( 'name' => 'core/edit-site' ) );
+
+		$expected = array();
+		foreach ( $post_types as $post_type ) {
+			$expected[] = '/wp/v2/entity-actions?kind=postType&name=' . $post_type;
+		}
+		$this->assertSame( $expected, _wp_preload_entity_actions( array(), $context ), 'The actions of the post types of the screen are preloaded.' );
+	}
+
+	/**
+	 * Data provider for test_the_site_editor_preloads_the_actions_of_its_screen().
+	 *
+	 * @return array[]
+	 */
+	public static function data_site_editor_screens() {
+		return array(
+			'pages'         => array( '/page', array( 'page' ) ),
+			'page'          => array( '/page/12', array( 'page' ) ),
+			'templates'     => array( '/template', array( 'wp_template' ) ),
+			'template'      => array( '/wp_template/emptytheme//index', array( 'wp_template' ) ),
+			'patterns'      => array( '/pattern', array( 'wp_block', 'wp_template_part' ) ),
+			'pattern'       => array( '/wp_block/12', array( 'wp_block' ) ),
+			'template part' => array( '/wp_template_part/emptytheme//header', array( 'wp_template_part' ) ),
+			'root'          => array( '/', array() ),
+			'styles'        => array( '/styles', array() ),
+			'navigation'    => array( '/navigation', array() ),
+		);
+	}
+
+	/**
+	 * The site editor preloads the actions of the edited post, once, next to
+	 * those of its screen.
+	 *
+	 * @ticket 66343
+	 */
+	public function test_the_site_editor_preloads_the_actions_of_the_edited_post() {
+		$_GET['p'] = '/page';
+		$context   = new WP_Block_Editor_Context(
+			array(
+				'name' => 'core/edit-site',
+				'post' => self::factory()->post->create_and_get( array( 'post_type' => 'page' ) ),
+			)
+		);
+
+		$this->assertSame(
+			array( '/wp/v2/entity-actions?kind=postType&name=page' ),
+			_wp_preload_entity_actions( array(), $context ),
+			'The actions of pages are preloaded once.'
+		);
+	}
+
+	/**
+	 * Other editors, a post editor context without a post, and a site editor
+	 * screen that lists no posts are left untouched.
 	 *
 	 * @ticket 66343
 	 */
 	public function test_other_editors_do_not_preload_the_actions() {
-		$context = new WP_Block_Editor_Context( array( 'name' => 'core/edit-site' ) );
+		$site_editor = new WP_Block_Editor_Context( array( 'name' => 'core/edit-site' ) );
+		$no_post     = new WP_Block_Editor_Context( array( 'name' => 'core/edit-post' ) );
+		$widgets     = new WP_Block_Editor_Context( array( 'name' => 'core/edit-widgets' ) );
 
-		$this->assertSame( array( '/wp/v2/types' ), _wp_preload_entity_actions( array( '/wp/v2/types' ), $context ), 'The paths are unchanged.' );
+		$this->assertSame( array( '/wp/v2/types' ), _wp_preload_entity_actions( array( '/wp/v2/types' ), $site_editor ), 'The paths of the site editor root are unchanged.' );
+		$this->assertSame( array( '/wp/v2/types' ), _wp_preload_entity_actions( array( '/wp/v2/types' ), $no_post ), 'The paths of a post editor without a post are unchanged.' );
+		$this->assertSame( array( '/wp/v2/types' ), _wp_preload_entity_actions( array( '/wp/v2/types' ), $widgets ), 'The paths of the widgets editor are unchanged.' );
 	}
 
 	/**
diff --git a/tests/phpunit/tests/entity-fields/wpPreloadEntityFields.php b/tests/phpunit/tests/entity-fields/wpPreloadEntityFields.php
index 064fbbf063566..58593c5727c36 100644
--- a/tests/phpunit/tests/entity-fields/wpPreloadEntityFields.php
+++ b/tests/phpunit/tests/entity-fields/wpPreloadEntityFields.php
@@ -32,12 +32,13 @@ public function test_the_fields_are_preloaded_on_the_block_editor_preload_paths(
 	}
 
 	/**
-	 * The post editor does not preload the fields, whatever its `p` query arg.
+	 * The post editor preloads the fields of the edited post type, which the
+	 * post summary of its inspector reads, whatever its `p` query arg.
 	 *
 	 * @ticket 66229
 	 */
-	public function test_the_post_editor_does_not_preload_the_fields() {
-		$_GET['p'] = '/page';
+	public function test_the_post_editor_preloads_the_fields_of_the_post_type() {
+		$_GET['p'] = '/wp_template';
 		$post      = self::factory()->post->create_and_get( array( 'post_type' => 'page' ) );
 		$context   = new WP_Block_Editor_Context(
 			array(
@@ -46,7 +47,7 @@ public function test_the_post_editor_does_not_preload_the_fields() {
 			)
 		);
 
-		$this->assertSame( array(), _wp_preload_entity_fields( array(), $context ) );
+		$this->assertSame( array( '/wp/v2/entity-fields?kind=postType&name=page' ), _wp_preload_entity_fields( array(), $context ) );
 	}
 
 	/**