- Star Trek: The Motion Picture
- Star Trek II: The Wrath of Khan
- Star Trek III: The Search for Spock
- Star Trek IV: The Voyage Home
- Star Trek V: The Final Frontier
- Star Trek VI: The Undiscovered Country
- Star Trek Generations
Chief of Starfleet Operations on Earth in the early 2370s whose brilliant career unraveled due to paranoia over an anticipated Changeling invasion. Benjamin Sisko served as first officer under Leyton on the U.S.S. Okinawa, and it was Leyton who later recommended Sisko for the posting as commander of Deep Space 9. In 2372 Leyton became obsessed over the possibility that the Dominion Founders might be infiltrating Starfleet, perhaps even the Federation government itself. Failing to convince Federation President Jaresh-Inyo to adopt repressive security measures, Leyton engineered a plan to create fear by faking evidence that a Dominion invasion was imminent. Leyton's plan would have culminated with a military coup of Earth's civilian government. When Ben Sisko, then serving on Earth as acting Starfleet security chief, discovered evidence of Leyton's plan, Leyton dispatched the Starship Lakota to destroy Sisko's Defiant, in order to prevent that evidence from reaching Earth. Leyton's plot collapsed when Lakota captain Erika Benteen refused to obey Leyton's orders to destroy the Defiant with all hands.