diff --git a/src/wp-includes/rest-api.php b/src/wp-includes/rest-api.php
index 7b615e5a5f..99cdd3e749 100644
--- a/src/wp-includes/rest-api.php
+++ b/src/wp-includes/rest-api.php
@@ -1552,6 +1552,7 @@ function rest_stabilize_value( $value ) {
  *              Support the "minItems", "maxItems" and "uniqueItems" keywords for arrays.
  *              Validate required properties.
  * @since 5.6.0 Support the "minProperties" and "maxProperties" keywords for objects.
+ *              Support the "multipleOf" keyword for numbers and integers.
  *
  * @param mixed  $value The value to validate.
  * @param array  $args  Schema array to use for validation.
@@ -1691,9 +1692,16 @@ function rest_validate_value_from_schema( $value, $args, $param = '' ) {
 		}
 	}
 
-	if ( in_array( $args['type'], array( 'integer', 'number' ), true ) && ! is_numeric( $value ) ) {
-		/* translators: 1: Parameter, 2: Type name. */
-		return new WP_Error( 'rest_invalid_param', sprintf( __( '%1$s is not of type %2$s.' ), $param, $args['type'] ) );
+	if ( in_array( $args['type'], array( 'integer', 'number' ), true ) ) {
+		if ( ! is_numeric( $value ) ) {
+			/* translators: 1: Parameter, 2: Type name. */
+			return new WP_Error( 'rest_invalid_param', sprintf( __( '%1$s is not of type %2$s.' ), $param, $args['type'] ) );
+		}
+
+		if ( isset( $args['multipleOf'] ) && fmod( $value, $args['multipleOf'] ) !== 0.0 ) {
+			/* translators: 1: Parameter, 2: Multiplier. */
+			return new WP_Error( 'rest_invalid_param', sprintf( __( '%1$s must be a multiple of %2$s.' ), $param, $args['multipleOf'] ) );
+		}
 	}
 
 	if ( 'integer' === $args['type'] && ! rest_is_integer( $value ) ) {
@@ -2298,6 +2306,7 @@ function rest_get_endpoint_args_for_schema( $schema, $method = WP_REST_Server::C
 		'maximum',
 		'exclusiveMinimum',
 		'exclusiveMaximum',
+		'multipleOf',
 		'minLength',
 		'maxLength',
 		'pattern',
diff --git a/tests/phpunit/tests/rest-api/rest-controller.php b/tests/phpunit/tests/rest-api/rest-controller.php
index 74364064e6..d6dc7f8fae 100644
--- a/tests/phpunit/tests/rest-api/rest-controller.php
+++ b/tests/phpunit/tests/rest-api/rest-controller.php
@@ -281,7 +281,7 @@ class WP_Test_REST_Controller extends WP_Test_REST_TestCase {
 			$this->assertArrayHasKey( $property, $args['somestring'] );
 		}
 
-		foreach ( array( 'minimum', 'maximum', 'exclusiveMinimum', 'exclusiveMaximum' ) as $property ) {
+		foreach ( array( 'multipleOf', 'minimum', 'maximum', 'exclusiveMinimum', 'exclusiveMaximum' ) as $property ) {
 			$this->assertArrayHasKey( $property, $args['someinteger'] );
 		}
 
diff --git a/tests/phpunit/tests/rest-api/rest-schema-validation.php b/tests/phpunit/tests/rest-api/rest-schema-validation.php
index 5889341c7b..77a2c2ec14 100644
--- a/tests/phpunit/tests/rest-api/rest-schema-validation.php
+++ b/tests/phpunit/tests/rest-api/rest-schema-validation.php
@@ -435,6 +435,42 @@ class WP_Test_REST_Schema_Validation extends WP_UnitTestCase {
 		$this->assertSame( 'param must be between 10 (inclusive) and 20 (inclusive)', $error->get_error_message() );
 	}
 
+	/**
+	 * @ticket 51022
+	 *
+	 * @dataProvider data_multiply_of
+	 *
+	 * @param int|float $value
+	 * @param int|float $divisor
+	 * @param bool      $expected
+	 */
+	public function test_numeric_multiple_of( $value, $divisor, $expected ) {
+		$schema = array(
+			'type'       => 'number',
+			'multipleOf' => $divisor,
+		);
+
+		$result = rest_validate_value_from_schema( $value, $schema );
+
+		if ( $expected ) {
+			$this->assertTrue( $result );
+		} else {
+			$this->assertWPError( $result );
+		}
+	}
+
+	public function data_multiply_of() {
+		return array(
+			array( 0, 2, true ),
+			array( 4, 2, true ),
+			array( 3, 1.5, true ),
+			array( 2.4, 1.2, true ),
+			array( 1, 2, false ),
+			array( 2, 1.5, false ),
+			array( 2.1, 1.5, false ),
+		);
+	}
+
 	/**
 	 * @ticket 50300
 	 */
diff --git a/tests/phpunit/tests/rest-api/rest-test-controller.php b/tests/phpunit/tests/rest-api/rest-test-controller.php
index 88c0ce7779..04732100a4 100644
--- a/tests/phpunit/tests/rest-api/rest-test-controller.php
+++ b/tests/phpunit/tests/rest-api/rest-test-controller.php
@@ -46,6 +46,7 @@ class WP_REST_Test_Controller extends WP_REST_Controller {
 				),
 				'someinteger'    => array(
 					'type'             => 'integer',
+					'multipleOf'       => 10,
 					'minimum'          => 100,
 					'maximum'          => 200,
 					'exclusiveMinimum' => true,