Powerful alien entity encountered by the Enterprise in the Star Trek episode "The Squire of Gothos". Trelane took the appearance of an early 19th-century fop, spoke in an affected manner, and regarded his conflict with the ship's crew as a game played for his amusement. James T. Kirk located and destroyed the source of Trelane's power and defeated him; in the end it was revealed that he was merely a child, and his even more powerful alien parents came and took him home.

He reappeared in the Star Trek: Next Generation novel Q-Squared, where we learned that Trelane was part of the Q Continuum.