Thomas Cavanagh was born October 26, 1963, and is a Canadian actor best known as the protagonist and title character in the NBC television program Ed as well as for his recurring role as the "Dog Boy" in Providence.

Cavanagh received a Golden Globe nomination and a TV Guide Award for his work on Ed. In 2002, he starred in the Showtime film Bang Bang You're Dead, which won a Peabody Award.

He was born in Ottawa, Canada, and moved with his parents to a small village in Ghana when he was six. In his teens, the family moved to Montreal where he started high school. While attending Queen's University in Ontario, he became interested in theater and music and played ice hockey and basketball. He graduated with degrees in English, biology and education.

In 1989 he was cast in a Broadway revival of Shenandoah. His stage credits also include productions of Grease, A Chorus Line, Cabaret, Brighton Beach Memoirs, and Urinetown.

He has long been known in Canada as an actor in television commercials, appearing for Labatt in the 1990s and more recently for CIBC.

In 2002, Cavanagh guest starred on the sitcom Scrubs. He was hired to play Dan Dorian, the brother of lead character J.D. (Zach Braff), because of his uncanny resemblance to Braff. He returned for one episode in 2003 and again for a two-episode arc in 2004.

In 2005, Cavanagh began filming for the CBS show Love Monkey whose cast also included Jason Priestley, Judy Greer, and Larenz Tate.