The original run of The X-Files included 217 episodes over nine seasons, meaning there were a lot of opportunities for guest stars. Creator Chris Carter did not let those opportunities pass, often nabbing already big names for an extraterrestrial experience or turn with a creepy monster-of-the-week.
Filmed in Vancouver, British Columbia, there were also a lot of yet-discovered and soon-to-be huge stars, including a teenage Ryan Reynolds and a very young Lucy Liu.
MORE: An ode to The X-Files, 30 years after the show premiered
Let’s get into some of the biggest cameos and guest-starring roles, but please note this is by no means all-inclusive.
1
Seth Green
Season: 1
Year: 1993
Episode: Deep Throat
Character: Emil
What you may know them from: The Italian Job, Austin Powers: International Man of Mystery, Family Guy
Notes: Green plays a stoner that shows Mulder the best place to sneak through the fence and delivers a great monologue about spaceships showing up to Saddam Hussein’s house using a hamburger as a prop.
2
Aaron Paul
Season: 9
Year: 2001
Episode: Lord of the Flies
Character: David ‘Sky Commander Winky’ Winkle
What you may know them from: Breaking Bad
Notes: Rounded out the second of the two Breaking Bad leads having an episode on The X-Files. Paul plays the Johnny Knoxville-esque character of a Jackass-like show.
3
Brad Dourif
Season: 1
Year: 1994
Episode: Beyond the Sea
Character: Luther Lee Boggs
What you may know them from: The Lord of the Rings: The Two Towers, The Lord of the Rings: The King Returns, One Flew Over the Cuckoo’s Nest
Notes: A remarkably creepy performance from Dourif who plays a death row inmate with potentially psychic powers.
4
Ryan Reynolds
Season: 3
Year: 1996
Episode: Syzygy
Character: Jay De Boom
What you may know them from: Deadpool, Van Wilder, Welcome to Wrexham
Notes: Reynolds doesn’t make it past the cold open as he’s murdered by a pair of best friends that are definitely big into astrology.
5
Felicity Huffman
Season: 1
Year: 1993
Episode: Ice
Character: Dr. Nancy DaSilva
What you may know them from: Desperate Housewives
Notes: Things go poorly for Huffman at a remote scientific site that has been taken over by a terrifying primordial worm that makes people rage-filled. If you like John Carpenter’s The Thing, you’ll love this episode.
6
Titus Welliver
Season: 1
Year: 1994
Episode: Darkness Falls
Character: Doug Spinney
What you may know them from: Gone Baby Gone, The Town, Argo, Bosch
Notes: A very young Welliver plays an eco-terrorist that is dedicated to keeping loggers from destroying the forest. Doesn’t stop him from being targeted from some not so fun bugs.
7
Shia LaBeouf
Season: 7
Year: 1999
Episode: The Goldberg Variation
Character: Richie Lupone
What you may know them from: Transformers, The Peanut Butter Falcon, Honey Boy
Notes: LaBeouf plays sick child Richie, who is friends with Willie Garson’s Weems — the luckiest guy in the world.
8
B.D. Wong
Season: 3
Year: 1996
Episode: Hell Money
Character: Detective Glen Chao
What you may know them from: Jurassic Park, Law & Order
Notes: Wong plays a detective helping Mulder and Scully track down why some men are turning up missing body parts.
9
Lucy Liu
Season: 3
Year: 1996
Episode: Hell Money
Character: Kim Hsin
What you may know them from: Charlie’s Angels, Set It Up
Notes: She doesn’t get a ton of screen time, but Liu is the sick daughter of a man willing to put his life — and eyes — on the line to win money to get her proper care.
10
Peter Boyle
Season: 3
Year: 1995
Episode: Clyde Bruckman’s Final Repose
Character: Clyde Bruckman
What you may know them from: Everybody Loves Raymond, While You Were Sleeping
Notes: An unwilling psychic that can only see how someone will die, Boyle absolutely steals the show in this episode. His scenes with Gillian Anderson are particularly wonderful.
11
Luke Wilson
Season: 5
Year: 1998
Episode: Bad Blood
Character: Sheriff Hartwell
What you may know them from: Legally Blonde, Old School, The Royal Tenenbaums
Notes: Wilson plays the handsome (or is he?) local sheriff (or is he?) of a small town that seems to have a vampire problem (or does it?).
12
Jesse Ventura and Alex Trebek
Season: 3
Year: 1996
Episode: Jose Chung’s From Outer Space
Character: Man In Black #1, Man In Black #2
What you may know them from: Predator, Jeopardy
Notes: It’s hard to think of a more eclectic or random pairing for a couple Men In Black, but it works.
13
Maggie Wheeler
Season: 1
Year: 1994
Episode: Born Again
Character: Det. Sharon Lazard
What you may know them from: Friends
Notes: After a handful of detectives are murdered, questions come up as to how they’re interconnected and related to a little girl.
14
Danny Trejo
Season: 8
Year: 2000
Episode: Redrum
Character: Cesar Ocampo
What you may know them from: Con Air, Machete, Sons of Anarchy
Notes: When a friend of Agent Doggett’s is living his days backwards, we find out that Trejo might actually be at the center of the murder being investigated.
15
Jane Lynch
Season: 9
Year: 2001
Episode: Lord of the Flies
Character: Anne T. Lokensgard
What you may know them from: Role Models, Glee, Party Down, The Marvelous Mrs. Maisel
Notes: Lynch is hiding a terrifying secret, and it’s something she’s passed on to her son.
16
Terry O'Quinn
Seasons: 2, Movie, 9
Years: 1995, 1998, 2002
Episodes: Aubrey, The X-Files: Fight the Future, Trust No 1
Characters: Lieutenant Brian Tillman, Darius Michaud, Shadow Man
What you may know them from: Lost, Millennium
Notes: No, you’re not reading that wrong. They used O’Quinn, who is fantastic, three separate times in three separate roles over the course of the series.
17
Jack Black
Season: 3
Year: 1995
Episode: D.P.O.
Character: Bart ‘Zero’ Liquori
What you may know them from: The Super Mario Bros. Movie, School of Rock, The Holiday
Notes: Best friend to the titular Darin Peter Oswald, Black is perfect in the role of arcade supervisor.
18
Bryan Cranston
Season: 6
Year: 1998
Episode: Drive
Character: Patrick Crump
What you may know them from: Breaking Bad, Malcolm in the Middle
Notes: The absolute worst backseat driver, but we’ll let it slide seeing as he’s dealing with a high pitch frequency only he can hear.
19
Giovanni Ribisi
Season: 3
Year: 1995
Episode: D.P.O.
Character: Darin Peter Oswald
What you may know them from: Friends, That Thing You Do, Saving Private Ryan
Notes: When you get struck by lighting, you may pick up some new skills.
20
Bradley Whitford
Season: 2
Year: 1994
Episode: Firewalker
Character: Daniel Trepkos
What you may know them from: Billy Madison, The West Wing
Notes: Things go horribly awry at a volcanic research site when a fungus that creates spores that explode through your throat starts to spread through the crew.
21
Dean Norris
Season: 2
Year: 1995
Episode: F. Emasculata
Character: Marshal Tapia
What you may know them from: Breaking Bad
Notes: A no-nonsense U.S Marshal that faces a horrifying virus that gives those infected terrifying, pulsating boils.
22
Willie Garson
Seasons: 3, 7
Years: 1995, 1999
Episodes: The Walk, The Goldberg Variation
Characters: Roach, Henry Weems
What you may know them from: Sex and the City
Notes: Another actor that played a couple different roles over the course of the season. His turn as the lead in The Goldberg Variation is delightful as he lives a life that is inconveniently lucky.
23
R. Lee Ermey
Season: 3
Year: 1995
Episode: Revelations
Character: Reverend Patrick Findley
What you may know them from: Full Metal Jacket, Mississippi Burning
Notes: Gunnery Sgt. Ermey doesn’t last long after faking stigmata in a church.
24
Michael Buble
Season: 3
Year: 1996
Episode: Piper Maru, Apocrypha
Character: Submarine Sailor
What you may know them from: Being a massive singing sensation
Notes: You have to really be looking for him, but he’s in a couple scenes as they flashback to the submariners who have some not so great luck with the black oil underwater. As a Vancouver native, it makes sense for Buble to make an appearance in a show that filmed almost exclusively in that area.
25
Octavia Spencer
Season: 7
Year: 1999
Episode: Millennium
Character: Nurse
What you may know them from: Hidden Figures, The Help, Fruitvale Station
Notes: A very, very “oh my gosh, that’s Octavia Spencer” moment as Frank Black (Lance Henriksen) tells her that he will be checking himself out of the psychiatric hospital to help our fave agents prevent the Four Horsemen of the Apocalypse.
26
Jayne Atkinson
Season: 2
Year: 1995
Episode: Fearful Symmetry
Character: Willa Ambrose
What you may know them from: Criminal Minds, House of Cards, 24
Notes: Atkinson plays a zoologist that has a bunch of animals abducted by aliens. Plus, there’s an invisible elephant.
27
Tony Shalhoub
Season: 2
Year: 1995
Episode: Soft Light
Character: Dr. Chester Ray Banton
What you may know them from: Monk
Notes: Don’t step into his shadow. Trust me.
28
Bruce Campbell
Season: 6
Year: 1999
Episode: Terms of Endearment
Character: Wayne Weinsider
What you may know them from: Army of Darkness, The Evil Dead
Notes: Known for his horror work, Campbell is excellent as a man with a devilish alter-ego that just wants what anyone might: to settle down and have a (non-demon) baby.
29
Charles Nelson Reilly
Season: 3
Year: 1996
Episode: Jose Chung’s From Outer Space
Character: Jose Chung
What you may know them from: All Dogs Go to Heaven, The Wind in the Willow, The Pink Panther
Notes: A really quirky episode that is made even more perfect by Reilly’s performance.
30
Michael McKean
Season: 6
Year: 1998
Episode: Dreamland I/II
Character: Morris Fletcher
What you may know them from: A Mighty Wind, Better Call Saul, Clue, This is Spinal Tap
Notes: In one of the funniest couple of episodes of The X-Files, Mulder and Fletcher swap bodies. He struggles to convince Scully who is who as Fletcher redecorates Mulder’s apartment back in Washington, DC (and makes a move on Scully!).
31
John O'Hurley
Season: 5
Year: 1997
Episode: The Post-Modern Prometheus
Character: Dr. Pollidori
What you may know them from: Seinfeld
Notes: O’Hurley is the perfect mad scientist for a black-and-white episode that involves Jerry Springer, peanut butter sandwiches and Cher.
32
Ed Asner
Season: 6
Year: 1998
Episode: How the Ghosts Stole Christmas
Character: Maurice
What you may know them from: The Mary Tyler Moore Show, Elf, Up
Notes: Along with our next entry, Asner played one half of a pair of ghosts dead set (pun intended) on finding new victims to share Christmas with them.
33
Lily Tomlin
Season: 6
Year: 1998
Episode: How the Ghosts Stole Christmas
Character: Lydia
What you may know them from: 9 to 5, 80 for Brady, Grace and Frankie
Notes: She’s a legend. What can you say?
34
CCH Pounder
Season: 2
Year: 1994
Episode: Duane Barry
Character: Agent Lucy Kazdin
What you may know them from: The Shield, Sons of Anarchy
Notes: Never mess with a CCH Pounder character. She runs the hostage situation after Duane Barry stops by a travel agency because he can’t figure out how to get to the alien abduction site.
35
Burt Reynolds
Season: 9
Year: 2002
Episode: Improbable
Character: Mr. Burt
What you may know them from: Smoky and the Bandit, Boogie Nights, Deliverance
Notes: Man, Burt Reynolds was just so cool.
36
Joe Morton
Season: 8
Year: 2000
Episode: Redrum
Character: Martin Wells
What you may know them from: Terminator 2: Judgement Day, Scandal, Speed
Notes: Morton plays a guy whose life is falling apart in reverse after learning he is in prison for killing his own wife. Can he prevent it from happening? Will anyone believe him?
37
Richard Belzer
Season: 7
Year: 1997
Episode: Unusual Suspects
Character: John Munch
What you may know them from: Law & Order: SVU, Scarface
Notes: If you wanted proof that the Law & Order, The Wire and X-Files universes are one in the same, here you go. Belzer plays the same character in all three series.
38
Jodie Foster
Season: 4
Year: 1997
Episode: Never Again
Character: Betty
What you may know them from: The Silence of the Lambs, Taxi Driver, Contact, Inside Man
Notes: We never see Foster, but she voices the evil tattoo of a man that Scully meets in Philadelphia.
39
Garret Dillahunt
Season: 5
Year: 1998
Episode: Travelers
Character: Edward Skur
What you may know them from: Justified, Raising Hope
Notes: This episode features a lot of time hopping, and Dillahunt is perfect in the role.
40
Lance Henriksen
Season: 7
Year: 1999
Episode: Millennium
Character: Frank Black
What you may know them from: Aliens, Millennium
Notes: Henriksen was the lead in a series that shared a name with this episode, and this crossover served as a finale for that show.
