Who played Trelane in 'The Squire of Gothos'?

William Campbell played Trelane in “The Squire of Gothos.” Campbell portrays the mysterious ruler as an elegant, theatrical, and childishly cruel figure who treats the Enterprise crew as playthings.

The episode follows the Enterprise after it encounters a rogue planet hidden from its sensors. Kirk, Sulu, and other crew members are transported to Trelane’s elaborate castle, where apparently impossible objects and environments appear at his command. Trelane initially seems omnipotent, but the story gradually suggests that his powers have limits.

Campbell’s performance is deliberately flamboyant, combining exaggerated manners with sudden threats. That contrast makes Trelane unsettling: he behaves like an aristocratic host while casually tormenting his guests. The episode aired on January 12, 1967, as the seventeenth episode of the first season.

Campbell later returned to Star Trek in a different role, playing the Klingon captain Koloth in “The Trouble with Tribbles” and “The Day of the Dove.” That recurring casting can cause confusion, but Trelane is specifically Campbell’s character in “The Squire of Gothos.”