As an actor, Thompson's only Broadway appearance was as drifter Hal Carter in "Summer Brave", William Inge's revised version of his play "Picnic". He portrayed Ranger Matt Harper on NBC’s 1974 series "Sierra" and Dr. Phil Parker on ABC's "Westside Medical". He appeared on the NBC soap opera "Somerset" as Tony Cooper and in the television films "The Rimers of Eldritch" and "F. Scott Fitzgerald and The Last of the Belles". Other acting credits include roles in the Bob Fosse movie "Star 80" and "Next Stop Wonderland", directed by Brad Anderson.