The Toronto-born Lamberts performed at the Stratford Festival in the 1960s and later joined the Shaw Festival at Niagara-on-the-Lake, where he gave a widely praised performance in the title role of Cyrano de Bergerac. In 2003, he starred as Oscar in the Canadian premiere of Neil Simon's Oscar and Felix -- A New Look at the Odd Couple. His awards include the Order of Canada and the Dora Mavor Moore Award for his performance in One for the Pot in 1996. On Broadway, he also appeared in the 1996 revival of Once Upon a Mattress.
Lamberts' recent film and television credits include Whitewash: The Clarence Brandley Story, More Tales of the City, and Tom and Huck.