John Fitzgerald Byers

 is a fictional conspiracy theorist and a recurring character featured on the FOX Network television series The X-Files. He was also one of the main characters on the short-lived spin-off series, The Lone Gunmen. Played by actor Bruce Harwood, he first appeared in the 17th episode of season one of The X-Files, "E.B.E.". The character was killed off in the fifteenth episode of season nine, "Jump the Shark".