McKellar has emerged as a filmmaker in his own right; his directorial debut, Last Night (1998), garnered impressive critical acclaim, winning the Prix de la Jeunesse at the Cannes Film Festival and the Claude Jutra Award at the Genies. In 2001, he played the role of Oliver Tapscrew in the TV children's drama series I Was a Rat. His second film, Childstar, opened in 2004 at the Toronto International Film Festival to enthusiastic reviews.