William Clemens (September 10, 1905 - April 29, 1980) was an American film director, known primarily for low-budget crime dramas.

Born in Saginaw, Michigan, Clemens began his Hollywood career as a film editor in 1931. His first directing project was Man Hunt in 1936. His major credits include On Dress Parade with the Dead End Kids, two Perry Mason mysteries (The Case of the Velvet Claws and The Case of the Stuttering Bishop), three films featuring detective Tom Lawrence, aka "The Falcon," four films based on the Nancy Drew series, and Calling Philo Vance.

Clemens' final project was The Thirteenth Hour in 1947. He died in Los Angeles, California.