His first lead role on the stage was as Finch in How to Succeed in Business Without Really Trying for the St. Joseph's Summer Music Theatre Festival.
[3] On television, after playing Waylin the slave in Hercules and the Lost Kingdom, the second of five TV movies, Trebor rose to fame playing the merchant Salmoneus, a character originating on Hercules: The Legendary Journeys and making occasional crossovers to sister show Xena: Warrior Princess.
The Los Angeles Weekly gave the show its prized "GO" recommendation and said, "actor Robert Trebor reincarnates Gottlieb in a 45-minute late-night solo performance that paints Brother Theodore's belligerent reflections on a twisted life with broad yet powerful comedic strokes."
Trebor starred as the Russian Major Viktor Davidykov in the drama Ravensridge by TS Cook.
Trebor is the author of The Haircut Who Would Be King which parodies Donald Trump and his relationship with Vladimir Putin.