The California Highway Patrol said the 63-year-old was pulled over near Los Angeles International Airport after an officer spotted him making an illegal right turn against a red light.
He was arrested after the officer smelled alcohol in the rental car.
The Sheriff's Inmate Information Centre said Cassidy was released on 15,000 US dollars (£9,110) bail and is scheduled to appear in court on February 5.
Cassidy appeared in TV's The Partridge Family from 1970 to 1974 and was a recording star and teen idol.
Cassidy's publicist was not immediately available for comment.