Stiles Oliver Clements (March 2, 1883 – January 15, 1966) was an architect practicing in Los Angeles and Southern California.

Clements trained at the École des Beaux-Arts, Paris.

He was a key figure in the 1920s Art Deco architectural movement, and 1930s Streamline Moderne style, in Los Angeles.

Clements was a partner with Octavius Morgan and John Walls in the firm of Morgan, Walls & Clements, known for his exuberant themed designs that included the Mayan Theater and Wiltern Theatre, and the famous Art Deco Richfield Tower.

He formed the firm of Stiles Clements & Associates.