The Heart of Texas Ryan, aka The Light of Western Stars, is a 1917 American silent Western film starring Tom Mix and Bessie Eyton and directed by E.A.

The film was produced by Sanford Productions.

It is Tom Mix's first feature-length film.

The film was re-released in 1923 as Single Shot Parker, a title by which it is sometimes called when marketed on home video and DVD.

The story centers on a love relationship between sharpshooting cowboy Jack "One Shot" Parker and Texas Ryan.