We recently asked members of the BuzzFeed Community which actors they've been surprised to learn were in certain movies. Here are the best responses that will make you go, "Whoa, I did not realise that!"
1. Stanley Tucci in Beethoven (1992)
"I watched that movie a lot as a kid and then largely forgot about it until I had to babysit my cousin's son. He wanted to watch that, I figured it was better than Spongebob for the third time, and HOLY CRAP Stanley Tucci!!" –Mye Logan, Facebook
3. Donnie Wahlberg in The Sixth Sense (1999)
"His name was included in the opening credits, but then I didn't see him anywhere in the movie. It wasn't until the very end that I realized he was the scary-skinny, terrified man in the opening scenes. I did not recognize him at ALL." –tomkat41
4. Robin Wright in Forrest Gump (1994) and The Princess Bride (1987)
"Embarrassed to admit it took 1.5 seasons of watching House of Cards to realize that Claire Underwood is actually Jenny from Forrest Gump – a movie I've watched countless times growing up." –Nikolina Burazer, Facebook.
"And more importantly, Princess Buttercup in The Princess Bride." –Chris Tucker, Facebook
5. Lena Headey (Cersei in Game of Thrones) in St Trinian's (2007)
"St Trinian's was on the TV the other day, and only when the credits rolled did we discover that the awkward, twittery teacher is LENA BLOODY HEADEY. As in, Cersei Lannister. I didn't even recognise her!" –Stephanie Wright, Facebook
6. Also Lena Headey in The Jungle Book (1994)
"One that got me and my sister was that Lena Headey (Cersei from Game of Thrones) was Kitty from The Jungle Book (1994)." –Ria Parton, Facebook
7. Mila Kunis (as a young Angelina Jolie) in Gia (1998)
–James Soares, Facebook
8. Kirsten Dunst in Jumanji (1995)
"I always knew she looked familiar but it took me forever to realise who she was." –lucyjane182
10. Glenn Close in Hook (1991)
"Glenn Close in Hook totally blew my mind – watched it my whole life before finding this out as an adult!" –Sarah Purser, Facebook
11. Also Kelly Rowan in Hook (1991)
"Kirsten Cohen (Kelly Rowan) from The O.C. was in Hook (very briefly as Peter's mother)." –Sarah Whitlock, Facebook
12. Liam Cunningham in A Little Princess (1995)
"Liam Cunningham, Captain Crewe in A Little Princess went on to co-star in Game of Thrones as Davos Seaworth. My jaw pretty much hit the ground. He looks so different!" –Becky Martin, Facebook
13. Anthony Head in Sweeney Todd: The Demon Barber of Fleet Street (2007)
"Anthony Head is in Sweeney Todd for five seconds. After the Pirelli v. Sweeney showdown, he approaches Sweeney and asks if he has his own establishment. Literally has just one line, no name, and is never seen again." –Lucy Anne, Facebook
14. Miley Cyrus in Big Fish (2003)
"Miley Cyrus was in Big Fish as a girl behind bushes with a crowd of kids. In the credits, her name is Destiny Cyrus." –Melissa Taylor, Facebook
15. Tom Felton in The Borrowers (1997)
"Tom Felton was (Peagreen) in The Borrowers. Was severely shook when I realised that." –Phoenix Heron, Facebook
16. Justin Theroux in Romy and Michele's High School Reunion (1997)
"Justin Theroux is the hot stuttering cowboy in Romy and Michele's High School Reunion. I could not believe it. I had to check IMDb while watching it." –Megan Linnea Grable, Facebook
17. Taryn Manning and Zoe Saldana in Crossroads (2002)
"Crossroads. As in, the Britney Spears movie. Hello Zoe Saldana and Pennsatucky from Orange Is the New Black! Taryn Manning is so good at lovable ragamuffins." –Stephanie Wright, Facebook
18. Christian Bale in Mio in the Land of Faraway (1987)
"I even watched it when I was older and said, 'Hey, that kid looks a lot like Christian Bale,' and thought nothing of it." –Jamie Wenner, Facebook
19. He was also in Little Women (1994)
20. Brie Larson and Ashley Benson in 13 Going On 30 (2004)
"Brie Larson in 13 Going on 30! I rewatched it the other day and had a bit of a freakout moment! She was also in Sleepover with a very young Evan Peters!" –kerrygill95
21. Taylor Momsen in How the Grinch Stole Christmas (2000)
"Taylor Momsen played Cindy Lou Who in How the Grinch Stole Christmas before starring as Jenny in Gossip Girl!" –larueisabella
22. Seth Rogen in Donnie Darko (2001)
"I love that movie and after a recent rewatch I was like, 'Holy crap, that's Seth Rogen!'" –Ryan Morris, Facebook
23. Angela Lansbury in Gaslight (1944)
"A 17-year-old Angela Lansbury film Gaslight (a classic, you should all watch it)! I find it crazy to see Jessica Fletcher/Mrs. Potts as a girl and yet somehow looking almost exactly the same." –Rebecca Ross, Facebook
24. Chris Messina in You've Got Mail (1998)
"In the scene where Meg Ryan visits Fox Books for the first time, he played the clueless salesperson." –Janhavi Deshpande, Facebook
25. Ryan Gosling in Remember the Titans (2000)
"Ryan Gosling is one of the supporting football players in Remember the Titans. I realised that on my 5,196th viewing of that movie, told my family members who were watching it with me, and we all freaked out." –Mary Grace Buckley, Facebook
26. Angela Bassett in Kindergarten Cop (1990)
"Angela Bassett as a freakin' flight attendant in Kindergarten Cop!" –Allyson Guy, Facebook
27. Kelly Bishop in Dirty Dancing (1987)
"Emily Gilmore (Kelly Bishop) in Gilmore Girls was in Dirty Dancing." –Sarah Whitlock, Facebook
28. Jack Black in Dead Man Walking (1995)
"He plays Sean Penn's younger brother." –Marie Suzanne Todd, Facebook
29. Chandra Wilson in Philadelphia (1993)
"Chandra Wilson (i.e. Grey's Anatomy's very own Miranda Bailey!!) in the tearjerker Philadelphia!" –Rossi Redgrave, Facebook
30. Abigail Breslin in The Princess Diaries 2: Royal Engagement (2004)
"Abigail Breslin as the little orphan girl in Princess Diaries 2." –Kirsty L. Powell, Facebook
31. Bryan Cranston in That Thing You Do! (1996)
–Vivian Le, Facebook
32. Julianna Hough in Harry Potter (2001)
"Julianne Hough in Harry Potter always freaks me out." –Chandler Nash, Facebook
33. John Krasinski in The Holiday (2006)
–Janae Mancheski, Facebook
35. Ben Affleck in the Buffy the Vampire Slayer movie (1992)
–Angela Wiltsie, Facebook
36. Steve Carell in Curly Sue (1991)
"Steve Carrell as a waiter in Curly Sue!" –Kailani Torres, Facebook
38. Lino Facioli (Robyn Arryn in Game of Thrones) in Get Him to the Greek (2010)
"Lino Facioli, who plays Robyn Arryn on Game of Thrones, plays Russell Brand's kid in Get Him to the Greek." –insomniamama
42. Tobey Maguire in The Wizard (1989)
"Tobey Maguire was in this bitchin' 1989 movie called The Wizard that was basically just a giant promotion for Super Mario Bros 3. Oh, and he had an amazing mullet." –punchandpie
CORRECTION
An earlier version of this post had a picture of Caroline Goodall as Peter's mother in Hook rather than Kelly Rowan. This has now been replaced with a correct picture. She really was in it for a snapshot so apologies for this error!