San Quentin is a 1937 Warner Bros. drama film directed by Lloyd Bacon and starring Pat O'Brien, Humphrey Bogart, and Ann Sheridan.

Red arrives in San Quentin and fights hardened criminal "Sailor Boy" Hansen in the courtyard on his first day.

May begins a romantic relationship with Jameson, and finds out he is the yard captain in charge of the prisoners.

Jameson institutes a system to separate the hapless lawbreakers from the hardened criminals, and assigns Joe work outside of the prison in a road construction camp.

Former chief guard Lieutenant Druggin resents Jameson, and surreptitiously assigns Hansen to the road camp as well.