McCarthy was born in Providence, Rhode Island at Women and Infants Hospital, grew up in Rumford, Rhode Island and attended St. Margaret's School and La Salle Academy. Described by The New York Times as a "John Belushi-like madman", McCarthy began performing stand-up comedy after graduating from Fordham University where he was the mascot, The Ram, from 1999 to 2001. McCarthy is known for having red hair and a beard. He portrayed The Cable Guy in a series of Verizon FiOs commercials. He appeared as a contestant on an episode of the television show Cash Cab, which aired on June 26, 2006. McCarthy hosts Action Pack Wednesday nights on AMC with Nick Stevens, and performed stand-up comedy at Just for Laughs and on television on Season 3 of Live at Gotham and John Oliver's New York Stand Up Show on Comedy Central. Coined the phrase, "You have got some brass, son!" in a St. Patrick's Day commercial for Guinness. McCarthy writes and performs with Front Page Films with Pete Holmes and Oren Brimer. The group has made videos for Doritos, Crunch Fitness, CollegeHumor, and Comedy Central. Front Page's HOTEL and DOCTOR series was featured on Atom.com. McCarthy appears in IFC's The Whitest Kids U' Know and with fellow comedian Robert Kelly of Curb Your Enthusiasm on HBO.