Which actor played FBI agent Fox Mulder on The X-Files?

David Duchovny played FBI agent Fox Mulder on The X-Files.

Duchovny portrayed Mulder from the series premiere in 1993 and became one of the show’s defining stars. Mulder is a trained FBI profiler who believes extraterrestrials and a government conspiracy explain many of the cases filed as X-Files.

The character’s partnership with Dana Scully created the show’s central dramatic tension: Mulder pursued extraordinary possibilities, while Scully demanded scientific evidence. Duchovny’s performance helped balance Mulder’s obsessive believer persona with dry humor and vulnerability.

Duchovny was a full-time lead through the first seven seasons. He later reduced his involvement, and Robert Patrick joined the main cast as John Doggett during the eighth and ninth seasons. That change can cause confusion, but Patrick played Doggett—not Mulder. Duchovny returned for the series finale and later revival seasons.