1. Bryan Cranston
Before Breaking Bad, Bryan Cranston gave a jaw-dropping performance in Season 6’s “Drive” as Patrick Crump, a man infected with a mysterious condition that causes fatal pressure buildup unless he keeps moving west. Hijacking Mulder in a frantic escape, his fear and desperation practically leap off the screen. The role demanded intensity, vulnerability, and an eerie charm, which Cranston delivered in every second of his screen time.
What fans didn’t know then was that this very performance would land him the role of Walter White. Vince Gilligan, who wrote the episode, saw the potential and never forgot it. Watching “Drive” now feels like watching history being made, one episode that proved Cranston could shift from everyday man to unpredictable force. The X-Files didn’t just guest-star him; it quietly revealed one of TV’s most iconic actors before the world caught on.
2. Aaron Paul
Before the world knew him as Jesse Pinkman, Aaron Paul stepped into The X-Files universe in Season 9’s “Lord of the Flies.” He played Sky Commander Winky, a thrill-seeking teen who led a group of misfit pranksters. While the episode leaned quirky, Paul delivered raw magnetism, making an otherwise odd plot memorable. His energy, timing, and screen presence hinted that he was more than just another high school troublemaker.
Even with limited screen time, he brought an unforgettable edge to a supporting role. It wasn’t just humor, it was control, rhythm, and subtle charisma. You could already see the layers that would later win him Emmys and global recognition. Watching this episode now feels like watching lightning strike twice, especially knowing he would one day share top billing with fellow X-Files alum Bryan Cranston in Breaking Bad.
3. Jane Lynch
Jane Lynch’s role in The X-Files is easy to overlook, but fans of hers should definitely rewind to Season 9’s “Lord of the Flies.” She plays a troubled mother coping with her son’s grotesque and bizarre transformation. The episode is packed with sci-fi weirdness, but Lynch grounds the story with honesty and control. Even amid the surreal chaos, her performance feels sincere, giving the storyline a much-needed emotional anchor.
Before she became a household name through her iconic role in Glee, Lynch was already mastering the art of being relatable in strange environments. Her acting style, understated yet deeply present, makes this one of the most grounded performances in a very eccentric episode. Looking back, it’s a fascinating preview of the dry wit and strength she would bring to so many characters in her later career.
4. Jack Black
In Season 3’s “D.P.O.,” Jack Black plays Bart Liquori, a lightning-obsessed teen who serves as sidekick to a deadly superpowered friend. Dressed in oversized clothes and brimming with Gen X sarcasm, Black slides effortlessly into the role of a small-town slacker. But what stands out isn’t just the humor. His onscreen charm and infectious energy jump off the screen, offering a glimpse of the star he was about to become.
This wasn’t just a bit part. It was a sneak peek into the controlled chaos that would become his brand. While the storyline gets dark, Black balances it with that signature mix of absurdity and heart. Watching him in The X-Files today is like discovering a secret origin story, one where a future comedy legend briefly walked through the shadowy halls of sci-fi television before taking center stage.
5. Giovanni Ribisi
Giovanni Ribisi takes center stage in “D.P.O.” alongside Jack Black, portraying Darin Oswald, a moody teenager who can control lightning. It’s a grim role, and Ribisi doesn’t flinch from the darkness. His portrayal captures the torment and loneliness of a young man who lashes out with deadly force. The episode is eerie, but Ribisi’s depth makes it something more: a disturbing portrait of grief, rage, and misunderstood power.
Rather than leaning into stereotypes, he adds complexity to a role that could have been a one-note villain. Ribisi lets you see the confusion beneath the cruelty, the boy beneath the monster. For many, this was their first exposure to an actor who would later shine in Saving Private Ryan, Avatar, and Sneaky Pete. Looking back, it’s a chilling performance that still resonates with longtime X-Files fans today.
6. Ryan Reynolds
In the Season 3 episode “Syzygy,” a young Ryan Reynolds plays Jay DeBoom, a high school jock who finds himself in the middle of a dark supernatural mystery. The role is small, and his character doesn’t last long, but even then, Reynolds had a certain spark. With just a few lines, he managed to add humor, charm, and a sense of mischief to an otherwise eerie storyline.
It’s the kind of role most actors would forget, but fans haven’t. What’s striking is how Reynolds already showed his signature mix of sarcasm and likability. Years before Deadpool and romantic comedies made him a household name, he was already leaving his mark. Watching him in The X-Files today feels like discovering a movie star at the exact moment before takeoff. It’s a blink-and-you’ll-miss-it moment worth rewatching.
7. Lucy Liu
Lucy Liu made a short but powerful appearance in Season 3’s “Hell Money,” playing Kim Hsin, a young woman suffering from leukemia. The episode explores a horrifying underground organ lottery targeting the vulnerable, and Liu’s character becomes a quiet but central figure in the tension. She’s not flashy, but her presence is unforgettable. You can feel the quiet strength she brings to every line and reaction.
It’s a deeply emotional role that shows Liu’s early ability to convey resilience without overacting. That same grace would later define her career in Ally McBeal, Kill Bill, and Elementary. Watching her in this small role gives you the sense that she was already ready for bigger things. It’s a haunting, underrated performance that holds up just as well as the show’s scarier moments.
8. Seth Green
Seth Green shows up early in The X-Files timeline in Season 1’s “Deep Throat.” He plays Emil, a stoner teen who claims to have witnessed strange lights in the sky near a military base. The episode leans into classic UFO territory, and Green’s performance adds a touch of levity. With his shaggy hair and sleepy charm, he nails the vibe of a kid who saw too much but isn’t taken seriously.
What’s cool about this cameo is how it fits right into Seth Green’s career trajectory. Even in this short scene, you see the beginnings of his sarcastic humor and subtle delivery. It feels like a warm-up to his later work in Robot Chicken, Austin Powers, and Buffy the Vampire Slayer. For longtime fans, his cameo is an unexpected treat that’s aged surprisingly well.
9. Lucy Lawless
Lucy Lawless made a strong impression in Season 9’s “Nothing Important Happened Today,” playing Shannon McMahon, a mysterious super-soldier with aquatic powers. She appears out of nowhere, dragging a man underwater with terrifying ease, all while maintaining an eerie calm. Her performance was menacing but grounded, adding a new layer to the show’s ongoing mythology during its later, more experimental seasons.
Best known as Xena: Warrior Princess, Lawless brought a commanding presence that elevated what could have been just another sci-fi baddie. She wasn’t there for long, but her character left a lasting impression. Fans of hers saw the muscle and mystery they loved, now paired with eerie stillness and control. Her scenes in The X-Files feel like a bridge between her warrior legacy and her later, more villainous roles.
10. Octavia Spencer
Octavia Spencer’s role in The X-Files may have been small, but it was one of her earliest steps toward a remarkable career. She appeared in the Season 7 episode “Millennium,” playing a nurse working in a psychiatric hospital. Though she only had a few lines, Spencer made the most of every moment, giving warmth and realism to a role many would’ve played flat.
It’s always fascinating to watch big stars in their early days. Spencer didn’t need a spotlight to shine. Her grounded presence, calm delivery, and ability to react naturally hinted at her future as an Oscar-winning powerhouse. This wasn’t the kind of role that earns awards, but it quietly signaled what was coming. Rewatching it now, you’ll spot the makings of greatness tucked into a brief but memorable guest spot.
11. Shia LaBeouf
A very young Shia LaBeouf made his X-Files debut in Season 7’s “The Goldberg Variation,” playing Richie, a sick boy whose life is miraculously saved by a man with unbelievable luck. At just 13 years old, LaBeouf brought an innocent vulnerability to the role. He wasn’t the center of the episode, but his performance added real emotional stakes to a story rooted in superstition and mystery.
Even then, LaBeouf had something special. His facial expressions, his quiet reactions—they felt real and unforced. Watching this episode today, you get a glimpse of the actor he’d become. From Disney’s Even Stevens to films like Holes and Fury, his early X-Files appearance shows a young performer with the ability to connect deeply with audiences, even in a brief role surrounded by chaos and paranormal events.
12. Felicity Huffman
Before Desperate Housewives made her a household name, Felicity Huffman had a quiet, powerful role in The X-Files Season 1 episode “Ice.” She played Dr. Nancy Da Silva, one of several scientists trapped in an Arctic research station after discovering a parasitic organism. Huffman’s performance brought steady professionalism and emotional restraint to a tense, paranoia-driven story that remains a fan favorite.
What stood out was how natural she felt in the high-stress atmosphere. She wasn’t over-the-top or showy—just fully believable. That grounded energy is what made her such a force in later dramas. Watching her in this early role is a treat for anyone who admired her later Emmy-winning work. It’s also proof that The X-Files had a gift for casting future stars who brought authenticity to even the most outrageous plots.
13. Kathy Griffin
In the Season 7 episode “Fight Club,” Kathy Griffin takes on a double role as two women—Betty Templeton and Lulu Pfeiffer—whose mere proximity causes chaos and destruction. The concept was wild, but Griffin leaned into the absurdity with full force. Her physical comedy and quick-witted timing brought a layer of cartoonish fun to an episode that many fans still debate today.
Griffin’s roles have always danced between quirky and bold, and this one was no exception. Even when the plot went off the rails, she stayed consistent, offering a fearless performance that kept viewers curious. Whether you loved or cringed at the episode, Griffin proved she could commit to bizarre material without blinking. It’s a must-watch moment that showcases her early TV chops before she became a comedy icon and pop culture fixture.
14. CCH Pounder
In the Season 2 episode “Duane Barry,” CCH Pounder played Agent Kazdin, a Hostage Rescue Team leader brought in to manage an alien-obsessed hostage situation. The role required a no-nonsense presence, and Pounder delivered with quiet authority. She immediately stood out among the chaos, holding her own in a room full of panicked characters and high-stakes uncertainty.
What’s powerful about Pounder’s performance is that she didn’t try to steal the spotlight—she simply became it. Her ability to project leadership and calm under pressure would later define her roles in The Shield and NCIS: New Orleans. In just a few scenes, she left an impression that elevated the entire episode. Watching her here reminds fans how even the smallest roles on The X-Files could leave a lasting legacy when the actor brought real power to the screen.
15. Burt Reynolds
In one of the most unusual episodes of Season 9, “Improbable,” Burt Reynolds plays a mysterious man named Mr. Burt who seems to control patterns of fate, numbers, and maybe even reality itself. His performance is low-key and philosophical, a playful contrast to the chaos of the serial killer case unfolding around him. Watching Reynolds dance through scenes with a wink and smile adds a surreal quality to the mystery.
What makes this guest spot special is how effortlessly Reynolds adds layers of charm and wisdom. He doesn’t overpower the story; he glides through it, leaving viewers with more questions than answers. It’s a curious, magical episode, and Reynolds seems perfectly at home in the world of unexplained phenomena. For longtime fans, it’s a fun reminder of just how versatile and iconic he truly was.
16. Willie Garson
Willie Garson, best known for his role as Stanford Blatch on Sex and the City, made not one but two appearances on The X-Files. First, in Season 3’s “The Walk,” he played a disturbed soldier who claimed to be haunted by an unseen enemy. Later in Season 6’s “The Goldberg Variation,” he returned as a completely different character. Each time, Garson delivered charm, vulnerability, and a uniquely quirky presence.
What made his appearances so memorable was his ability to vanish into vastly different roles. He was funny when needed, serious when the tone shifted, and always believable. These weren’t leading roles, but they stuck with you. Garson was the kind of actor who elevated everything around him, even in just a few minutes of screen time. Watching him on The X-Files feels like a little hidden treasure in TV history.
17. Lily Tomlin
Comedy legend Lily Tomlin turned up in one of The X-Files’ most unusual ghost stories, Season 6’s “How the Ghosts Stole Christmas.” She starred alongside Ed Asner as Lyda, one of two spirits haunting a mansion that traps Mulder and Scully during Christmas Eve. Her performance was haunting, playful, and deeply human, adding heart to a story that easily could have veered into cliché or silliness.
Tomlin brought layers to her ghostly role—by turns manipulative, funny, and melancholic. She infused the character with personality and pathos, making viewers actually feel for someone who had long been dead. It wasn’t just a holiday special; it was a master class in tone. For fans of Tomlin’s long career, this episode is a reminder of how she could take even the strangest roles and give them soul.
18. Tony Shalhoub
Tony Shalhoub, long before his Emmy-winning run on Monk, gave a subtle and memorable performance in Season 2’s “Soft Light.” He played Dr. Chester Ray Banton, a physicist whose shadow literally kills anyone it touches. The episode explored paranoia, isolation, and quantum mechanics, and Shalhoub embodied a man both terrified of himself and desperate to protect others. It was science fiction with serious emotional weight, driven by his grounded performance.
What stands out about Shalhoub’s role is how restrained and powerful it feels. He wasn’t flashy, but he didn’t need to be. Every glance, pause, and hesitation made you believe he was carrying something dangerous and tragic. Long before he became one of television’s most beloved detectives, he was already proving that subtlety can sometimes be the most powerful choice. This episode remains a standout for fans of thoughtful sci-fi drama.