[1] Gantt got his start in the entertainment business working in the art department and props while training as an actor and director at the Beverly Hills Playhouse under Milton Katselas.

[2] His credits on television shows and films include Criminal Minds, American Horror Story: Hotel, Ocean's Eleven, Charlie's Angels: Full Throttle, Buffy The Vampire Slayer, Dexter, Major Crimes, and a role in The Arrangement on E!.

In 2010 Gantt directed two episodes of the branded series, Suite 7 with Shannen Doherty, Dexter’s Jaime Murray, Warehouse 13's Eddie McClintock[8] and in 2011, the award-winning short film Donor starring Trevor Algatt and Alexis Boozer.

[13] In 2021 Gantt co-wrote the Audible series A Devil in the Valley, alongside Paul Holes, and retired FBI Special Agent Jim Clemente.

[14] Mark Gantt and Brianne Davis launched Secret Life, a podcast that discusses love, sex, money, food, addiction, and hidden taboos.