David William Duchovny is an American actor, writer, producer and musician. He portrayed FBI agent Fox Mulder on the television series The X-Files and played the writer Hank Moody on the television series Californication (2007–2014), both of which have earned him Golden Globe awards. Duchovny appeared in both X-Files films—the 1998 science fiction-thriller of the same name and the supernatural-thriller The X-Files: I Want to Believe (2008). He executive-produced and starred in the historically based cop drama Aquarius (2015–2016).

Fox William Mulder is a fictional FBI Special Agent and the secondary protagonist of the Fox science fiction-supernatural television series The X-Files, played by David Duchovny. Mulder's peers dismiss his many theories on extraterrestrial or paranormal activity as those of a conspiracy theorist and supernaturalist; however, his skeptical but supportive partner, Special Agent Dana Scully, often finds them to be unexpectedly correct. He and Scully work in the X-Files office, concerned with unsolved FBI cases that are often revealed to be supernatural or extraterrestrial in nature. Mulder was a main character for the first seven seasons, but was limited to a recurring character for the following two seasons. He returns as a main character for the tenth and eleventh seasons.