Dean Winters is an American actor. Best known for his role as Ryan O'Reily on the HBO prison drama Oz, he has also appeared on such television series as Rescue Me, 30 Rock, and Law & Order: Special Victims Unit, as well as the character "Mayhem" in a series of Allstate Insurance commercials. Winters co-starred with Josh Duhamel in one season of the CBS Network series cop drama Battle Creek...
(wikipedia)