Macdonald, a longtime stand-up comedian and actor, appeared in films such as Billy Madison, Doctor Dolittle, and Funny People.
He created and starred in The Norm Show, which aired on ABC from 1999 to 2001. Other television credits include NewsRadio, The Drew Carey Show, and The Orville.
Macdonald was a regular on the late night talk show circuit and he was one of the first mainstream comedians to launch a video podcast.
Celebrities and comedians reacted to news of his death: