Macdonald was born and raised in Adelaide, South Australia, to an English mother and a New Zealand father, and was educated at Pasadena High School.

Macdonald has since acted in a wide variety of Australian television and movies, most notably his portrayal of Constable Tim Dewey in Underbelly: The Golden Mile.

[3] Although American Burger received mixed reviews from critics, its technical aspects were praised,[4] along with the audio and cinematography.

He has portrayed Andre Roussimoff in Sky Arts' Urban Myths series, appearing in the episode Waiting for Andre alongside David Threlfall in late 2016 and matricide killer Ross Taggart in the Channel 5 series Countdown to Murder.

The production company had found great difficulty in finding the right actor to play Larry, and he was personally sought out by director and writer Tigmanshu Dhulia for the role.