Mackenzie Gray was born and raised in Toronto. A professional actor for over 40 years, he has appeared in over 150 films and television shows. As of 2017, he is a series regular on the Marvel/FX Series Legion (2017) playing "The Eye" and is a recurring cast member on both the CW series Riverdale (2016) as "The Pathologist" and plays "The Time Master" on DC's Legends of Tomorrow (2016).

Since moving to Vancouver in 1998 as a series lead for the television series The Net(1998), he has appeared as a guest star in scores of Vancouver or Calgary-filmed productions, recently including the BBC America/Netflix series Dirk Gently's Holistic Detective Agency (2016), Fargo (2014), R.L. Stine's The Haunting Hour (2010), Alcatraz(2012), and Project Mc² (2015). He returned to Toronto to Guest-Star in the series Bitten(2014).