The X-Files is an iconic show to come out of the early '90s, and the combination of mythology stories and Monster of the Week episodes created enough of a hit to last nine original seasons, two revival seasons, and two feature films. David Duchovny and Gillian Anderson aren't the only big names to come out of the show, however, as a number of the guest stars went on to become stars of their own shows. Read on for the standouts!
Ryan Reynolds
Ryan Reynolds is known for big screen ventures like the Deadpool films nowadays, but The X-Files fans saw a very young version of the actor in the Season 3 episode “Syzygy” in 1996… briefly, anyway! His character was killed off before the end of the cold open, but Reynolds would go on to star in ABC’s hit Two Guys, a Girl and a Pizza Place sitcom from 1998-2001.
Bryan Cranston
Bryan Cranston proved a master of comedy with Malcolm in the Middle and of drama with Breaking Bad, but he flexed his acting muscles on The X-Files earlier on. While playing the ill-fated Patrick Crump in the Season 6 episode “Drive” wasn’t his first TV credit, the 1998 gig introduced him to executive producer Vince Gilligan, who would go on to cast Cranston as Walter White.
Jack Black
Long before School of Rock and The Super Mario Bros. Movie, Jack Black played Bart “Zero” Liquori in Episode 3 of The X-Files’ third season in 1995. He would later star in TV projects like Tenacious D between 1997-2000, The Brink in 2015, and the Kung Fu Panda: The Dragon Knight animated series from 2022-2023.
Terry O'Quinn
Terry O’Quinn portrayed three different franchise characters. He played Lt. Brian Tillman in the “Aubrey” episode of Season 2 in 1995, SAC Michaud in The X-Files: Fight the Future feature film, and Shadow Man in the “Trust No 1” episode of Season 9 in 2002. Best known now as John Locke on Lost from 2004-2010, he also recurred on shows including Hawaii Five-0, FBI: Most Wanted, and Resident Alien.
Luke Wilson
Luke Wilson holds a special place in the hearts of many X-Files fans for starring as the vampire sheriff Lucius Hartwell in arguably the show’s best episode: “Bad Blood” in 1998. Following that Season 5 episode, he landed multi-episode gigs on shows including That ‘70s Show and Roadies before starring in the DC Comics-based series Stargirl from 2020-2022.
Lucy Liu
Future Kill Bill actress Lucy Liu played Kim Hsin in The X-Files’ third season episode called “Hell Money” back in 1996. She debuted in her first series regular role on the sitcom Pearl later that year, but her big TV break would be Ling Woo on Ally McBeal before playing Dr. Joan Watson in CBS’ Elementary from 2012-2019.
Tony Shalhoub
Before he was an Emmy- and Tony Award-winner, Tony Shalhoub appeared in the Season 2 episode of The X-Files called “Soft Light” as the very stressed Dr. Chester Ray Banton. While he was already starring on NBC’s sitcom Wings at the time, his most acclaimed (and award-winning) work came later with Monk starting in 2002 and The Marvelous Mrs. Maisel starting in 2017.
Jane Lynch
The ninth season of The X-Files wasn't the most popular, but the “Lord of the Flies” episode in 2001 featured Jane Lynch as Mrs. Anne T. Lokensgard years before she introduced the world to Sue Sylvester on Fox’s Glee. For that role, she'd be nominated for three Emmys and win one over the course of six seasons from 2009-2015.
Felicity Huffman
Considering Felicity Huffman's later fame for Sports Night, American Crime, and Desperate Housewives, it can be easy to overlook her very early episode of The X-Files as Dr. Nancy Da Silva in 1993. The Season 1 episode was an homage to the iconic horror film The Thing and remains one of the show’s best more than thirty years later.
Shia LaBeouf
When one thinks of Shia LaBeouf as a child star, his lead role as Louis Stevens in Disney Channel’s Even Stevens from 2000-2003 probably comes to mind first. One year earlier, however, the future household name played a sick youngster by the name of Richie in a Season 7 episode of The X-Files called “The Goldberg Variation.”
CCH Pounder
While CCH Pounder only appeared as Agent Lucy Kazdin in one episode of The X-Files, Season 2's “Duane Barry” was pivotal. Starting later in 1994, Pounder appeared in the first four seasons of ER before arriving on The Shield in 2002. Her longest-running role has been playing NCIS: New Orleans' Dr. Loretta Wade for all seven seasons from 2014-2021.
BD Wong
While BD Wong appeared in Jurassic Park in the early ‘90s, small-screen stardom would take longer. He played Detective Glen Chao in The X-Files’ “Hell Money” episode of Season 3 in 1996, before he’d go on to a role in Oz from 1997-2003 and Law & Order: SVU starting in 2001. He’d eventually become one of the Law & Order stars to appear in most episodes.
Donal Logue
Donal Logue guest-starred in The X-Files' very first Monster of the Week episode, called “Squeeze,” in 1993. He went on to recur in later seasons of ER before starring in all five seasons of Grounded for Life and all five seasons of Gotham, which wrapped after 100 episodes in 2019.
Peter Boyle
Peter Boyle’s career goes back to the 1960s, but X-Files Season 3 fans will remember him for playing the title character in “Clyde Bruckman’s Final Repose” in 1995, for which he won an Emmy. He would then score another seven Emmy nominations for playing Frank Barone across nine seasons of Everybody Loves Raymond from 1996-2005.
Laurie Holden
Laurie Holden wasn’t a one-off guest star on The X-Files but would appear in ten episodes as Marita Covarrubias between 1996-2002. She’d become more of a household name as part of the original cast of The Walking Dead regulars, and she ranks among the Walking Dead cast members to appear in most episodes.
Aaron Paul
The future Breaking Bad star can be found in a Season 9 episode of The X-Files, called “Lord of the Flies” in 2001, where he played a character with the distinguished name of “Sky Commander Winky.” He would go on to recur on Big Love before landing his career-making role as Jesse Pinkman opposite Bryan Cranston. Post-Breaking Bad credits include The Path, BoJack Horseman, and Westworld.
Michael Emerson
Years before his Emmy-winning portrayal of Ben on Lost, Michael Emerson guest-starred in the final Monster of the Week episode of The X-Files’ original run. Called “Sunshine Days,” the Season 9 episode in 2002 preceded his guest stint on Without a Trace, his role in Saw, and of course five seasons of Lost. Other long-running roles since The X-Files include Person of Interest and Evil.
Jesse L. Martin
Jesse L. Martin arrived on The X-Files to play baseball-loving alien Josh Exley in “The Unnatural,” the Season 6 episode written and directed by David Duchovny in 1999. Later that year, Martin joined the cast of Law & Order, where he remained for nine seasons and nearly 200 episodes. The Flash was his next series regular gig until 2023, followed by The Irrational early in the 2024 TV lineup.
Bradley Whitford
While Bradley Whitford is likely best remembered for his work as Josh Lyman in The West Wing starting in 1999, he had a very different part to play in The X-Files’ second season in 1994. He portrayed the unfortunate Daniel Trepkos in “Firewalker.” Whitford has three Emmy wins to his name since the early ‘90s thanks to his work on The West Wing, Transparent, and The Handmaid’s Tale.
Paul McCrane
Paul McCrane played the titular character in the Season 4 episode called “Leonard Betts” in 1997. He’s also responsible for one of the most iconic lines in The X-Files history: “I’m sorry, but you’ve got something I need.” McCrane joined the cast of ER later that year to play Dr. Robert Romano across seven seasons, ending his time in one of the medical drama’s most memorable deaths.
Kurtwood Smith
Although he would later be quite well known for a different Fox series, Kurtwood Smith portrayed Agent Bill Patterson in the Season 3 episode called “Grotesque,” which aired on the network in 1996. Two years later, he was back on Fox for That ‘70s Show to play Red Forman for eight seasons and 200 episodes. Smith more recently reprised the role for Netflix’s That ‘90s Show.
Octavia Spencer
Octavia Spencer’s episode of The X-Files in 1999 may be better remembered as the one that delivered the first actual kiss between Mulder and Scully, but you can find the actress in the Season 7 episode titled “Millennium.” In addition to winning her Academy Award for The Help, Spencer landed many guest and recurring TV gigs before her lead role in Apple TV+’s Truth Be Told from 2019-2023.
Seth Green
Seth Green was a guest in the very first episode of The X-Files following the pilot, as Emil in “Deep Throat” in 1993. While it wasn’t his first TV role, it preceded his work as Oz on Buffy the Vampire Slayer from 1997-2000. He really hit his stride as a voice actor with Robot Chicken and Family Guy in particular, with hundreds of episodes of each show to his name.
Garrett Dillahunt
The X-Files is one of Garret Dillahunt’s earliest credits, as he played Edward Skur in the flashback-heavy Season 5 episode “Travelers” in 1998. He may be better remembered for his work in Deadwood which started several years later in 2004, followed by TV projects including all four seasons of Raising Hope, three seasons of The Mindy Project, and three seasons of Fear the Walking Dead.
Dean Norris
Dean Norris is a master of playing characters in law enforcement, including Marshal Tapia in The X-Files’ Season 2 episode “F. Emasculata” in 1995. His biggest TV break would come years later as Hank Schrader in Breaking Bad, and he appeared in all three seasons of CBS’ Under the Dome and all four seasons of TNT’s Claws before recurring in Law & Order: Organized Crime’s fourth season as well.
Lucy Lawless
Lucy Lawless’ most iconic work to date was likely as Xena in Xena: Warrior Princess for syndication from 1995-2001, but she came to network TV primetime in 2001 for two episodes of The X-Files Season 9 as alien super-soldier Shannon McMahon. She’d go on to recur across the last three seasons of Battlestar Galactica and become one of the faces of Starz’s Spartacus franchise of shows starting in 2010.
Brad Dourif
Brad Dourif is one of The X-Files’ most memorable early guest stars as serial killer Luther Lee Boggs in Season’s “Beyond the Sea” in 1991, but he really made a mark on TV starting in 2004 with playing Doc Cochran in Deadwood. More recently, he has been voicing the demonic doll himself in the Chucky series that premiered in 2021.
Bruce Campbell
After the Evil Dead films, Bruce Campbell was a perfect casting for a show like The X-Files in its sixth season. He played Wayne Weinsider in the twisted “Terms of Endearment” episode of 1999. Campbell would later spend seven seasons on USA as part of the Burn Notice cast, and – of course – reprise his role as Ash for all three seasons of the Ash vs Evil Dead TV show.
Willie Garson
The late Willie Garson played two different characters on The X-Files: Quinton “Roach” Freely in Season 3’s “The Walk” in 1995 and Henry Weems in Season 7’s “The Goldberg Variation” in 1999. His most well-known work is likely playing Stanford Blatch on Sex and the City across all six seasons starting in 1998. He would also star in all six seasons of USA’s White Collar following its 2009 premiere.
Giovanni Ribisi
Giovanni Ribisi certainly wasn’t unknown in television when he guest-starred as Darin Peter Oswald in Season 3 of The X-Files in 1995, but it was before he made his Friends debut as Frank Buffay Jr. More significantly, he starred in Fox’s Dads opposite Seth Green from 2013-2014 and then all three seasons of Prime Video’s Sneaky Pete from 2015-2019.
Mark Sheppard
Mark Sheppard only had a couple of credits in the entertainment industry to his name when he appeared as Cecil L’Ively in the Season 1 episode “Fire” in 1993. He then landed ongoing roles in shows like Soldier of Fortune, Inc., 24, and Battlestar Galactica, but he’s best known for portraying the fan-favorite demon Crowley on Supernatural for eight of the show’s fifteen seasons.
Danny Trejo
Danny Trejo came to The X-Files in Season 8 to play Cesar Ocampo in “Redrum” in the show’s early post-Mulder era. In addition to some film credits following TXF, he arrived on The Young and the Restless in 2008 and – most notably – Sons of Anarchy to play Romeo Parada starting in 2011. He’s also a prolific voice actor for shows including King of the Hill, The Adventures of Puss in Boots, and Big City Greens.
