Best known for his roles as FBI agent Fox Mulder on the popular science fiction series The X-Files and as alcoholic writer Hank Moody on Showtime's comedy/drama Californication. He's also appeared in the films Kalifornia, Evolution and Zoolander.
He received honors for his poetry from the Academy of American Poets while attending Princeton University.
He played a cross-dressing DEA agent named Denise Bryson in three episodes of the cult TV series Twin Peaks.
He married actress Tea Leoni in 1997. He and Leoni had a daughter named Madelaine in 1999 and a son named Kyd in 2002 before divorcing in 2014.
He and Gillian Anderson co-starred in The X-Files from 1993 to 2002, and it was announced in March 2015 that they would reprise their roles for a six-episode event series in 2016.