- NBC's hit sitcom "Friends" featured plenty of notable guest actors outside of its star-studded cast.
- The show's guest stars included Dakota Fanning, Brad Pitt, Sean Penn, and Gabrielle Union.
- Three "Riverdale" actors also appeared on the show: Cole Sprouse, Marisol Nichols, and Mark Consuelos.
- Bruce Willis even won an Emmy for his hilarious role as Paul Stevens on "Friends."
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"Friends" remains a bedrock of '90s and early '00s pop culture.
The show's main stars, like Jennifer Aniston and David Schwimmer, are still major players in Hollywood today. But what's really impressive is how many cameos by famous actors the series packed into its 10 seasons.
From then-current celebrities like Brad Pitt and Susan Sarandon, to future notables like Mae Whitman and Cole Sprouse, it seems like almost everyone working in Hollywood between 1994 and 2004 was on "Friends" at one point or another.
There is, however, a notable absence of actors of color. Until Gabrielle Union in the seventh season, hardly any black actors had a significant role.
Here are 66 guest stars you probably forgot were on "Friends."
Brad Pitt appeared on the show during season eight, while he was married to Jennifer Aniston.
He played an old friend named Will Colbert, who was the president of the "I Hate Rachel Green Club" in high school.
Leah Remini auditioned for Monica, but didn't get the role. Instead, she was in a scene from season one, in which Joey helped her give birth.
Remini appeared in the episode titled "The One With the Birth," which centered on Carol going into labor.
Charlie Sheen showed up as Phoebe's old flame and Navy sailor, Ryan.
Ryan and Phoebe both ended up getting chickenpox.
Danny DeVito played a stripper dressed as a cop at Phoebe's bachelorette party.
He was not what she expected.
Susan Sarandon appeared as a rising costar in Joey's daytime drama, "Days of Our Lives" — much to his chagrin.
Sarandon guest-starred on season seven, episode 15.
Alison Sweeney, who was in the real-life sitcom "Days of Our Lives," was also in the version of the show in the "Friends" universe.
Her character, Jessica Ashley, won a trophy for best supporting actress, but was a no-show at the awards ceremony.
Matthew Ashford, another "Days of Our Lives" star, made a cameo at a cast party for the "Friends" version of the show.
Rachel and Monica were both starstruck by the celebrities at the party.
Hugh Laurie got mad at Rachel over airplane manner protocols (and her bad relationship decisions).
Rachel encountered Laurie's character while on a plane. She was headed to Ross' wedding to tell him her true feelings.
While "Friends" was on the air, Helen Hunt was in "Mad About You." She played her character on "Friends," mistaking Phoebe for her twin sister, Ursula.
Lisa Kudrow herself was on "Mad About You" as Ursula Buffay.
Reese Witherspoon had an important role as Rachel's spoiled younger sister who broke the relationship dynamics in their lives.
She appeared on season six and the siblings argued over dating Ross.
Not to be outdone, Christina Applegate played Rachel's other sister, who was in need of help after her boyfriend problems.
Her name was Amy and she got into an argument with Rachel after saying that her daughter, Emma, wasn't cute.
David Arquette played Phoebe's twin sister's stalker in an episode from season three.
In real life, Arquette was married to Courteney Cox from 1999 to 2013.
Winona Ryder played Rachel's sorority sister and partner in her "big kiss."
Ryder appeared as Melissa Warburton on season three, episode three.
Anna Faris portrayed Erica, the birth mother of twins adopted by Chandler and Monica.
She appeared on a few episodes throughout season 10.
Aisha Tyler played Charlie Wheeler, who dated Joey but later ended up with Ross.
She appeared on episodes throughout the last two seasons of "Friends."
Paul Rudd had an even longer run on "Friends," as Phoebe's second husband.
They met after Joey set Phoebe up on a blind date during season nine.
Robin Williams and Billy Crystal teamed up as Tim and Thomas, two customers at Central Perk during season three.
They sat on the iconic coffee shop couch and kept interrupting Monica when she was trying to tell a story.
To legally change her name to Princess Consuela Banana-Hammock, Phoebe petitioned a clerk played by Craig Robinson.
In response, Mike changed his name to Crap Bag.
Julia Roberts, Chandler's childhood friend, returned to his life to date him for an episode.
She appeared on season two, episode 13, and pranked Chandler while on their date.
Roberts' "My Best Friend's Wedding" costar Dermot Mulroney appeared on a few episodes as Gavin Mitchell.
He was Rachel's coworker who liked her. The pair kissed during one episode but didn't explore a relationship because things were complicated between Rachel and Ross.
Action star Jean-Claude Van Damme played himself, as an actor filming a movie in New York.
Monica and Rachel had a crush on him.
Sean Penn played the fiancé of Phoebe's twin sister in two episodes from season six.
He had a brief fling with Phoebe, but the two ended their relationship because Phoebe having an identical twin sister made things confusing.
Gary Oldman was nominated for an Emmy for his role as Richard Crosby, a spittle-prone actor who costarred in a movie with Joey.
Oldman appeared on two episodes from season seven, in which Joey struggled to make it to Monica and Chandler's wedding in time due to the filming of the movie with his difficult costar.
Ross dated a student for a few episodes, and Bruce Willis stepped in as her father (who dated Rachel).
Willis earned an Emmy for his role as Paul Stevens on "Friends."
Ben Stiller had a memorable episode as Tommy — otherwise referred to as "The Screamer" — who was briefly Rachel's short-fused boyfriend.
He had almost everyone convinced that he was a nice guy, except for Ross. Tommy's true temperament was revealed when the friends saw him yell at Chandler and Joey's pet chicken and pet duck.
"Glee" star Jane Lynch cameoed as a real estate agent in a blink-and-you'll-miss-it role on season 10.
She showed Monica and Chandler a house.
Fellow "Glee" star Iqbal Theba appeared as a doctor on season five.
Theba played a doctor who informed Joey that he had kidney stones.
Dakota Fanning played Mackenzie, who used to live in a house Monica and Chandler were looking at.
She was 9 years old when she played the role.
In a callback to "ER," George Clooney and Noah Wyle played emergency room doctors.
They went on a double date with Monica and Rachel.
Jason Alexander, known for his role on "Seinfeld," played a character who wanted to commit suicide.
Phoebe tries to stop him and appeared to be successful.
Alec Baldwin played another one of Phoebe's boyfriends.
He was annoyingly optimistic about everything and Phoebe told him to be less happy.
Selma Blair played Chandler's flirty coworker in an episode where he was forced to spend Christmas in Tulsa.
She told Chandler that she was interested in him, even though he was married to Monica.
Jeff Goldblum, too, found a way to be on "Friends."
He directed Joey in a play and gave some acting advice.
Future "Suite Life of Zack and Cody" and "Riverdale" star Cole Sprouse played Ross' son, Ben, in seasons six through eight.
Sprouse and twin brother Dylan Sprouse were childhood actors who starred in movies like "Big Daddy" with Adam Sandler and guest-starred on "That '70s Show."
He's not the only "Riverdale" star who appeared on "Friends." Marisol Nichols (Hermione Lodge) showed up during season nine.
Nichols portrayed Joey's "Days of Our Lives" costar named Olivia.
Long before portraying Hiram Lodge on "Riverdale," one of Mark Consuelos' first roles was on "Friends."
He played a police officer who pulled Rachel over after she was caught speeding on season seven.
Actress and model Denise Richards played Ross' hot cousin.
Ross, Phoebe, and Chandler had a crush on her.
Sarah, Duchess of York, appeared as herself, taking a photo with Joey during season four.
They briefly met when the friends traveled to London for Ross and Emily's wedding.
English business mogul Richard Branson had a cameo on the same episode, as a street vendor.
He sold Joey a souvenir.
"That Girl" actress Marlo Thomas played Rachel's mom on a few episodes.
Monica forgot to invite her to Rachel's baby shower during season eight.
Australian model Elle Macpherson had a stint as Joey's girlfriend.
She became Joey's roommate after Chandler moved out, and he only picked her because of her looks.
Jim Rash, who later played the principal on the cult comedy "Community," played a nervous plane passenger on the final episode of the show.
He got scared after Phoebe called Rachel and said that there was something wrong with the plane's "left phalange," which was obviously a lie.
John Stamos played a potential sperm donor for Chandler and Monica.
They scared him away with all their invasive questions about his personal life and family history.
Chandler and Ross both had a crush on a character played by actress and producer Ellen Pompeo.
The "Grey's Anatomy" star played Missy Goldberg, who Ross and Chandler knew in college.
Adam Goldberg guest-starred for three episodes as Chandler's weird roommate.
Chandler met Eddie at a supermarket.
Chrissie Hynde, the founder of The Pretenders, wrote some songs with Phoebe.
She appeared on season two and performed at Central Perk.
Legendary actress and filmmaker Isabella Rossellini had a cameo as herself.
She missed out on Ross' list of celebrities he's allowed to sleep with.
Actress and former Victoria's Secret model Jill Goodacre also appeared as herself.
She was trapped in an ATM vestibule with Chandler during a blackout on season one.
Kristin Davis, known for her role as Charlotte on "Sex and the City," was one of Joey's dates on an episode.
Rachel and Phoebe liked her character a lot more than Joey did.
"Simpsons" star Hank Azaria was Phoebe's first major boyfriend.
He has a recurring role over a few seasons.
Fellow "Simpsons" voice actor Harry Shearer was also on the show, wanting to buy Ross' monkey.
He was only interested in buying Marcel to be part of an animal fighting ring.
Actress and model Rebecca Romijn played another one of Ross's dates.
Ross ended their relationship after going to her apartment and seeing how messy she was.
Future "Iron Man" director and Marvel star Jon Favreau played Monica's boyfriend during the third season.
Pete Becker was a millionaire who later took an interest in MMA fighting.
Similar to the Aisha Tyler plot, Gabrielle Union dated both Ross and Joey.
Ross and Joey met her character after she moved into a building near Central Perk.
"Saturday Night Live" and "30 Rock" actor Chris Parnell feuded with Chandler at his job.
For some unexplained reason, he called Chandler "Toby."
Phoebe married a Canadian ice dancer, played by Steve Zahn, to help him get a green card.
They later got a divorce because he fell in love with a woman who he actually wanted to marry.
Mae Whitman, who later starred in "Parenthood," acted as a Girl Scout.
Ross sold her Girl Scout cookies for her after accidentally breaking her leg.
Kyla Pratt, who voiced Penny Proud on "The Proud Family," had a fleeting role as another Girl Scout.
She was mad at Ross for harming her fellow Girl Scout.
"She's All That" star Freddie Prinze Jr. played a nanny named Sandy on season nine.
He would have been a great nanny for Emma, but Ross couldn't get over the fact that he was a male babysitter.
Tom Selleck played Richard Burke, Monica's eye-doctor-turned-boyfriend.
They had a large age gap and broke up because Monica wanted kids of her own and he didn't want more, having previously welcomed a son and daughter with his ex-wife.
"Dirty Dancing" star Jennifer Grey played Mindy, Rachel's best friend and maid of honor in her wedding to Barry that never happened.
Mindy actually went on to marry Barry, but they got divorced because he cheated on her (again).
"The Marvelous Mrs. Maisel" star Alex Borstein played the star of a one-woman show on season nine.
Chandler saw her play alone after the friends ditched him to go to a party.
"That '70s Show" star Debra Jo Rupp had a recurring role as Alice Knight.
She was married to Frank Buffay, Phoebe's half-brother. Phoebe gave birth to the couple's triplets during season five.
"Legally Blonde" star Jennifer Coolidge played Amanda Buffamonteezi, Monica and Phoebe's old roommate who returned during season 10.
She lived in England for a bit and pretended to have an accent, even though she was from Yonkers, NY.
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