Cassidy, 63, was pulled over Friday night after he exited the 405 freeway in Los Angeles and police saw him try to make an illegal right turn, TMZ.com reported.
The actor is best known for his role as Keith on the 1970s musical sitcom "The Partridge Family."
Police said Cassidy allegedly smelled of alcohol and failed a field sobriety test.
He was then given a Breathalyzer test and blew .19 -- more than twice the legal blood-alcohol content level, the report said.
In August, Cassidy was arrested in Schodack, N.Y., for drunk driving, People reported. He was also arrested in Florida in 2010 for the same crime.
After his New York arrest, Police Chief Bernhard Peter told People Cassidy "was cooperative. He was a total gentleman and didn't give us a problem whatsoever."
Cassidy's manager and publicist Jo-Ann Geffen issued a statement to Entertainment Tonight on Saturday that said, "David just completed a stint in rehab and was doing very well in sobriety. He was in Los Angeles to attend depositions by Sony Pictures Television, respondents in a lawsuit filed by Cassidy in 2011 over what he claims are monies long due him from Partridge Family merchandise, home video, etc. After attending his and his manager's depositions, it appears as if the pressure led to a brief relapse. He was on his way to the airport to return to his home in Florida and to transitional rehabilitation. He plans now to return to rehab in an undisclosed facility."