Chris Carter created The X-Files.
Chris Carter (screenwriter) . Carter went on to create three more series for the network -- Millennium , a doomsday-themed series which met with critical approval and low viewer numbers ; Harsh Realm , which was canceled after three episodes had aired ; and The Lone Gunmen , a spin-off of The X-Files which lasted for a single season . Carter 's film roles include writing both of The X-Files cinematic spin-offs -- 1998 's successful The X-Files and the poorly received 2008 follow-up The X-Files : I Want to Believe , the latter of which he also directed -- while his television credits have earned him several accolades including eight Primetime Emmy Award nominations . Harsh Realm . It was developed by Chris Carter , creator of The X-Files and Millennium , and began airing on the Fox Network on October 8 , 1999 .