diff --git a/src/wp-includes/rest-api/class-wp-rest-server.php b/src/wp-includes/rest-api/class-wp-rest-server.php
index 19b362a4ca..4e26611bb4 100644
--- a/src/wp-includes/rest-api/class-wp-rest-server.php
+++ b/src/wp-includes/rest-api/class-wp-rest-server.php
@@ -1308,6 +1308,8 @@ class WP_REST_Server {
 		$site_icon_id = get_option( 'site_icon', 0 );
 
 		$this->add_image_to_index( $response, $site_icon_id, 'site_icon' );
+
+		$response->data['site_icon_url'] = get_site_icon_url();
 	}
 
 	/**
diff --git a/tests/phpunit/tests/rest-api/rest-server.php b/tests/phpunit/tests/rest-api/rest-server.php
index f04c266425..aa927c8b1c 100644
--- a/tests/phpunit/tests/rest-api/rest-server.php
+++ b/tests/phpunit/tests/rest-api/rest-server.php
@@ -1084,6 +1084,7 @@ class Tests_REST_Server extends WP_Test_REST_TestCase {
 		// Check site logo and icon.
 		$this->assertArrayHasKey( 'site_logo', $data );
 		$this->assertArrayHasKey( 'site_icon', $data );
+		$this->assertArrayHasKey( 'site_icon_url', $data );
 	}
 
 	/**
diff --git a/tests/qunit/fixtures/wp-api-generated.js b/tests/qunit/fixtures/wp-api-generated.js
index 5c70e70c2b..00b6a2f834 100644
--- a/tests/qunit/fixtures/wp-api-generated.js
+++ b/tests/qunit/fixtures/wp-api-generated.js
@@ -10781,7 +10781,8 @@ mockedApiResponse.Schema = {
         }
     },
     "site_logo": 0,
-    "site_icon": 0
+    "site_icon": 0,
+    "site_icon_url": ""
 };
 
 mockedApiResponse.oembed = {