Dean Gerard Winters is an American actor. He is known for his role as Ryan O'Reily on the HBO prison drama Oz and his roles in the TV series Millennium, Rescue Me, 30 Rock, Sex and the City, and Law & Order: Special Victims Unit, as well as portraying "Mayhem" in a series of Allstate Insurance commercials. He co-starred in one season of the CBS Network cop drama series Battle Creek and had a recurring role as "The Vulture" on the comedy series Brooklyn Nine-Nine. He also appeared in the 2023 Netflix film The Out-Laws and the 2024 AMC series Monsieur Spade.