diff --git src/wp-includes/option.php src/wp-includes/option.php
index aa98477..2ac98bc 100644
--- src/wp-includes/option.php
+++ src/wp-includes/option.php
@@ -1737,16 +1737,18 @@ function register_initial_settings() {
 		'description'  => __( 'Site tagline.' ),
 	) );
 
-	register_setting( 'general', 'siteurl', array(
-		'show_in_rest' => array(
-			'name'    => 'url',
-			'schema'  => array(
-				'format' => 'uri',
+	if ( ! is_multisite() ) {
+		register_setting( 'general', 'siteurl', array(
+			'show_in_rest' => array(
+				'name'    => 'url',
+				'schema'  => array(
+					'format' => 'uri',
+				),
 			),
-		),
-		'type'         => 'string',
-		'description'  => __( 'Site URL.' ),
-	) );
+			'type'         => 'string',
+			'description'  => __( 'Site URL.' ),
+		) );
+	}
 
 	register_setting( 'general', 'admin_email', array(
 		'show_in_rest' => array(
diff --git tests/phpunit/tests/rest-api/rest-settings-controller.php tests/phpunit/tests/rest-api/rest-settings-controller.php
index ff91a60..9970e59 100644
--- tests/phpunit/tests/rest-api/rest-settings-controller.php
+++ tests/phpunit/tests/rest-api/rest-settings-controller.php
@@ -49,9 +49,9 @@ class WP_Test_REST_Settings_Controller extends WP_Test_REST_Controller_Testcase
 		$request = new WP_REST_Request( 'GET', '/wp/v2/settings' );
 		$response = $this->server->dispatch( $request );
 		$data = $response->get_data();
+		$actual = array_keys( $data );
 
-		$this->assertEquals( 200, $response->get_status() );
-		$this->assertEquals( array(
+		$expected = array(
 			'title',
 			'description',
 			'url',
@@ -67,7 +67,17 @@ class WP_Test_REST_Settings_Controller extends WP_Test_REST_Controller_Testcase
 			'posts_per_page',
 			'default_ping_status',
 			'default_comment_status',
-		), array_keys( $data ) );
+		);
+
+		if ( is_multisite() ) {
+			$expected = array_diff( $expected, array( 'url' ) );
+		}
+
+		sort( $expected );
+		sort( $actual );
+
+		$this->assertEquals( 200, $response->get_status() );
+		$this->assertEquals( $expected, $actual );
 	}
 
 	public function test_get_item_value_is_cast_to_type() {