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 and 1930s Streamline Moderne architectural movements in Los Angeles. He also designed in historicist motifs and revivalism styles, such as the Adamson House in the Spanish Colonial Revival and Moorish Revival styles.
Clements was a partner with Octavius Morgan and John Walls at Morgan, Walls & Clements, known for his exuberant themed designs that included the Mayan and Wiltern theaters, the Richfield Tower, and many others. In 1937, he formed the firm Stiles Clements & Associates.