- Is the son of two teachers.
- Brother Neil MacDonald is a CBC journalist.
- Began his career as a writer for Roseanne, before joining Saturday Night Live in 1993.
- Known for his impressions of Bob Dole and Burt Reynolds on Saturday Night Live.
- Let the f-word slip on an April 1997 episode of Saturday Night Live but was not fired (Charles Rocket was fired from the show for that same offense in 1981).
- Was fired from the Weekend Update segment of Saturday Night Live in December 1998 by NBC West Coast president Don Ohlmeyer over the phone because Ohlmeyer didn't find him funny.
- Plays poker on the celebrity poker circuit.
- Dylan MacDonald — Son
- Connie MacDonald — Ex-wife
- Neil MacDonald — Brother