John Garman "J. G." Hertzler Jr. (born March 18, 1950) is an American actor, author, screenwriter, and activist best known for his role on "" as the Klingon General (and later Chancellor) Martok, whom he portrayed from 1995 until the series' end in 1999.
John Garman was on Star Trek.
Based on the article it is unclear if he was on Star Trek. The system was confused by the information provided.