McKellar frequently acts in his own projects, and has also appeared in Atom Egoyan’s Exotica and David Cronenberg’s eXistenZ and Crimes of the Future.

He is also known for being a fixture on Canadian television, with series including Twitch City, Odd Job Jack, and Slings & Arrows, as well as writing the book for the popular Tony Award-winning musical The Drowsy Chaperone.

[1][2][3][4] He attended Glenview Senior Public School, Lawrence Park Collegiate Institute and later studied English at the University of Toronto's Victoria College.

McKellar made his first screen appearance in 1989 in Bruce McDonald's film Roadkill, for which he also wrote the screenplay, earning Genie Award nominations for best supporting actor and best screenwriter, attracting the attention of many in Canada.

McKellar is also a filmmaker in his own right; his directorial debut, Last Night (1998), which he also wrote and starred in, garnered impressive critical acclaim, winning the Prix de la Jeunesse at the Cannes Film Festival and the Claude Jutra Award at the Genies.

[7] In 2006, he appeared in Ken Finkleman's miniseries At the Hotel, received a Gemini Award nomination for his role as socialist politician Clarence Fines in Prairie Giant: The Tommy Douglas Story and hosted the CBC Radio One series High Definition.