Amassing nine seasons with a total of 202 episodes, The X-Files was one of TV's most popular shows of the 1990s. While the stars, David Duchovny and Gillian Anderson, became household names for many people, there were a surprising number of stars who showed up here and there throughout the show's run. Some came because they loved the show, others because they were connected to cast members or the crew in some way, like Tea Leoni, for example, who was married to Duchovny at the time. Going back and watching episodes nowadays, however, reveals that there were a great number of now-famous actors who took roles in the show at a time when they were virtual unknowns. While not all got famous from their role in The X-Files (most did not), some were noticed because of their performances and some partnerships formed during filming that would come into play again later on down the road.

We could go through and list every famous actor from then and now that ever appeared on The X-Files, but it might be more interesting to look at the stars who weren't famous or well-known at the time of their appearance, actors who have since become major stars in film and TV. There are some stars who were cut out of the list because they were in a grey area that we would like to mention. Some, like Seth Green and Jane Lynch, had been acting for quite a while before they appeared on The X-Files. It would be unfair to them and their fans to suggest they weren't well-known prior to, but, for those who didn't know them, we've at least mentioned them here. Then there are actors like Jewel Staite, who is a massive star for Firefly fans, but might be unrecognizable for those who never saw that masterpiece of a show. If you think we've missed someone, check to see if they could fall into one of those categories before yelling at us. If they still deserve to be here after you've checked, then start yelling. Here are 15 actors who appeared on The X-Files before they were famous.

15. Luke Wilson

It's a bit tough to nail down exactly when Luke Wilson became a well-known actor. We'd all like to think we recognized his talents from his very first films Bottle Rocket and Bongwater, but both of those films, despite being cult classics now, did not perform amazingly in their early days. Wilson had a few decent film roles around the same time as his X-Files episode "Bad Blood," such as in Scream 2 (a cameo) and Rushmore, but he wasn't really all that big of a star. It probably wouldn't be until the early 2000s that he blew up, about the same time as his brother Owen. But in 1998, Wilson would appear in X-Files as a Sheriff with some horrible teeth. His character and Mulder's reaction to the character were some of the best moments in that show and make Wilson's cameos one of the funniest on this list.

14. Bradley Whitford

Bradley Whitford has been around for a while. He was in Adventures of Babysitting, Revenge of the Nerds II and Scent of a Woman, all films that predate his role in The X-Files episode "Firewalker," but he definitely wasn't a "star," so to speak. After he appeared in The X-Files in 1994, Whitford played Eric Gordon, the antagonist, in Billy Madison and his stock grew. Then in 1999, Whitford was cast as White House Deputy Chief of Staff Josh Lyman in The West Wing, and his face would become forever cemented in the public's mind. Since then, Whitford has been in Cabin in the Woods, Saving Mr. Banks and, most recently, in the TV series Transparent. He might not have the biggest name, but almost everyone who watches films will recognize his face and his ability.

13. Felicity Huffman

Way back in season one of The X-Files, Desperate Housewives star Felicity Huffman showed up in an episode in which she is infected by a parasitic alien worm. Huffman would go on to appear in a few films, such as Magnolia and Christmas with the Cranks before nabbing the part of Lynette Scavo in Desperate Housewives, a role that would keep her in the spotlight for eight years. In terms of film, Huffman is best known for her role in Transamerica, a role that she earned an Academy Award nomination for. In Transamerica, Huffman also shared the screen with another X-Files alum, our next entry on the list.

12. Kevin Zegers

Kevin Zegers' acting talents may have not been recognized until he was in Transamerica with Felicity Huffman, but he has been around the block once or twice. He started acting as a young child and was cast to play the part of Kevin Kryder, a child who seemed to be connected to Jesus Christ in some mysterious way, in The X-Files episode "Revelations." The year after his appearance in The X-Files, Zegers would become known by children everywhere because of the Air Bud films, in which he starred in the first and three of the sequels. Zegers then was cast as Damian Dalgaard in the hit TV series Gossip Girl and, most recently, the film The Mortal Instruments: City of Bones.

11. Tony Shalhoub

When Tony Shalhoub showed up in The X-Files episode "Soft Light" in 1995, he had already been on the TV series Wings for a few years, but he wasn't the star of the show, so he wasn't necessarily a "star." That time wouldn't come until he landed the lead role in Monk in 2002. In between those points in time, Shalhoub had a recurring role in Men in Black and Men in Black II. Shalhoub's also been in Thirteen Ghosts, Spy Kids 1, 2 and 3. He's done some great voice work over the years as well, appearing in Cars 1 and 2 as Luigi and in Teenage Mutant Ninja Turtles as Splinter.

10. Doug Hutchison

Doug Hutchison's acting career has been slightly overshadowed by his real-world controversies. Early on in The X-Files, Hutchison had a recurring role as Eugene Tooms, a killer who takes new victims every 30 years. After that role, Hutchison garnered some acclaim for his role as Percy in The Green Mile. He also was in Con-Air, A Time to Kill and Batman & Robin all within a few years of each other. After that, Hutchison appeared on several huge shows, specifically Lost, playing the part of Horace Goodspeed. Then, in 2001, Hutchison's name was all over for his marriage to then-16-year-old Courtney Stodden. Hutchison was teaching an acting class when he met and connected with Stodden and their relationship began. When it was announced that they had married, Hutchison's career took a major hit, only appearing in a few roles since then. Now that Stodden is 22, it's possible that Hutchison will be able to reinvent himself a la Woody Allen, but only time will tell.

9. Laurie Holden

Before appearing in films The Mist, Silent Hill or the TV shows The Shield and The Walking Dead, Laurie Holden was playing the recurring character Marita Covarrubias in The X-Files. Holden is definitely most famous for her character Andrea Harrison in The Walking Dead, a role that started in 2008, but it was 12 years earlier that she caught the attention of fans in The X-Files. Starting in season four, Holden, as Covarrubias, worked for the Syndicate and became Mulder's informant after X (Steven Williams), Mulder's former mole, was killed.

8. Lucy Liu

Well before Lucy Liu was the superstar she is today, she had a few spots in TV shows, like Beverly Hills, 90210, Coach and Home Improvement. In 1995, Liu got a very small recurring part on ER and appeared in an episode of The X-Files. It wouldn’t be until 1998 that Liu's career really took off, landing the role of Ling Wiu in Ally McBeal and then appeared in Shanghai Noon and Charlie's Angels in 2000. In Liu's X-Files episode, the Chinese Mafia are behind a strange organ lottery and Liu plays a girl with Leukemia. BD Wong also appears in this episode long before his casting on Law & Order: Special Victims Unit, but Wong played the scientist Wu on Jurassic Park prior to this role, so he was pretty well known at that time.

7. Jack Black (& Giovanni Ribisi, too)

Jack Black had a few small roles before he was in The X-Files in 1995, but he never amounted to much until about 1999 or 2000 when he showed up in several big flicks like The Jackal, Enemy of the State and High Fidelity. We need to mention Giovanni Ribisi here as well because he was the star of the same episode as Jack Black, but he had been acting for quite a while before this point. Ribisi was one of the stars of The New Leave It to Beaver and My Two Dads, and he had a recurring role on the smash hit The Wonder Years. Still, it's impressive that two future stars came out of the same X-Files episode, ironically about lightning striking people.

6. Octavia Spencer

Despite showing up in many quality films and TV shows throughout her career, it wasn't really until 2011 with The Help that Octavia Spencer became a superstar. Spencer's debut role in acting was in A Time to Kill in which she played a nurse. Little did she know at the time, that would be a role she would do again, playing a nurse in ER, Brimstone, Chicago Hope, Roswell, Everything Put Together, What Planet Are You From?, Just Shoot Me, City of Angels, Grounded for Life, The Sky is Falling, Seven Pounds, Halloween 2, Red Band Society, Break a Hip and, you guessed it, The X-Files. For Spencer, it was way back in 1999 when she grabbed a pair of scrubs and played a nurse in The X-Files episode "Millennium."

5. Shia LaBeouf

Before the Vegas wedding, the plagiarism and Indiana Jones and the Kingdom of the Crystal Skull, before Transformers, Disturbia and Constantine, even before Holes and Even Stevens, Shia LaBeouf was on The X-Files. It wasn't his first big TV show because he was on Suddenly Susan and Touched by an Angel the same year, but LaBeouf was just a little boy on The X-Files playing Ritchie, a sick child in need of an organ donor. LaBeouf looks like a baby in this episode, fresh faced and bright-eyed. If only we could have told him then that he would go down a weird path when he gets older, but, then again, where's the fun in that? The potential of self-destruction is part of what makes following the Hollywood and celebrity lifestyle so intently so great.

4. Dean Norris

It may be a bit of slight on Dean Norris' career to suggest he wasn't famous before The X-Files, but he certainly wasn't Hank Schrader from Breaking Bad famous. Norris was in The X-Files back in 1995. Before that, he had some smaller roles in Lethal Weapon 2, Total Recall, Gremlins 2: The New Batch and Terminator 2: Judgement Day, but it would shock us if anyone knew his name at that point. Plus, Norris fits in with a neat little connection between The X-Files and Breaking Bad. Vince Gilligan, the creator of Breaking Bad, was a writer for The X-Files, writing 29 episodes beginning with "Soft Light" (the episode that starred Tony Shalhoub). Gilligan would also co-produce 44 episodes and would use some of the cast members in his other shows down the road, such as Dean Norris.

3. Aaron Paul

Keeping the Breaking Bad connection going, Aaron Paul, best known for playing Jesse Pinkman on Gilligan's Breaking Bad, was in an episode of The X-Files long before anyone knew who he was. In the same episode "Lord of the Flies," comedian Jane Lynch also appeared, though she had fairly decent film and TV roles behind her name by that time. As for Paul, it wasn't until he appeared in the TV series Big Love that he became a name in the industry. Keep in mind that in Breaking Bad, Jesse Pinkman was supposed to die in season one, but because the character grew on everyone, he stuck around until the end.

2. Bryan Cranston

Bryan Cranston has been acting since 1968, appearing in One Life to Live when he was 12-years old, but even he would tell you that no one knew who he was before Malcolm in the Middle, the show that he played Hal for six years beginning in 2000. Between 1968 and 2000, Cranston appeared in several shows, almost always in a one-time role, shows like CHiPs, Baywatch, L.A. Law and Texas Ranger. In 1994, Cranston became instantly more recognizable when he landed a small recurring role on Seinfeld as Tim Whatley, Jerry's dentist. Immediately after leaving that show, Cranston was cast in an episode of The X-Files, completing the Vince Gilligan and Breaking Bad connection. It should also be mentioned that coincidentally this episode was called "Drive," the same title of a film that Cranston would appear in 13 years later.

1. Ryan Reynolds

Between 1998 and 2002, Ryan Reynolds started to make a name for himself as an actor. In 1998, he landed the starring role in the TV series Two Guys, a Girl and a Pizza Place, which ran until 2001, a role followed up with the film National Lampoon's Van Wilder. Before that, however, even before his role in the TV movie Sabrina the Teenage Witch, Reynolds was on The X-Files. Back then, he didn't quite look like the person he looks like today. He was a bit squishier in those days, a little more round in the face as well. He did play a jock in the episode, but he was always crying and bellyaching, so it wasn't a very effective stereotype.

Sources: IMDB; TVGuide; XFilesWikia