1. Before starring in Game of Thrones, Natalie Dormer appeared as Private Lorraine, who stole a kiss from Steve Rogers, in Captain America: The First Avenger.
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2. Olivia Munn played a TV reporter at the Stark Expo in Iron Man 2.
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3. Ty Burrell starred as Leonard, Bruce Banner's friend and Betty's original love interest, in The Incredible Hulk.
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4. Miley Cyrus voiced Mainframe, a member of Stakar Ogord's team of Ravagers in Guardians of the Galaxy Vol. 2.
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5. Before starring in Crazy Rich Asians, Michelle Yeoh appeared in Guardians of the Galaxy Vol. 2 as Aleta Ogord, a Ravager captain.
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6. Happy Endings star Adam Pally played Gary, a cameraman who met Tony Stark in Iron Man 3.
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7. Kate Mara appeared as a US marshal in Iron Man 2.
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8. Comedian Garrett Morris made a cameo in Ant-Man as a cab driver — He famously parodied Ant-Man on Saturday Night Live.
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9. Doctor Who star Jenna Coleman appeared as Bucky's date to the Stark Expo in Captain America: The First Avenger.
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10. Community star Danny Pudi played a communications tech agent at S.H.I.E.L.D. in Captain America: The Winter Soldier.
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11. Nathan Fillion voiced the monstrous inmate that teased Peter Quill in Guardians of the Galaxy.
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12. Seth Green had a blink-and-you'll-miss-it cameo as a fan at the Stark Expo in Iron Man 2.
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13. Also, Seth voiced Howard the Duck in Guardians of the Galaxy Vol. 1 and Vol. 2.
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14. Jennifer Connelly voiced Karen, the interface that Tony installed in Peter's Spider-Man suit, in Spider-Man: Homecoming — she's also married to Paul Bettany IRL.
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15. Lou Ferrigno, who played The Hulk on the '90s TV series, appeared as a security guard in The Incredible Hulk.
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16. Chris O'Dowd appeared as Richard, a guy who tried to date Jane, in Thor: The Dark World.
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17. A Christmas Story star Peter Billingsley appeared in Iron Man as scientist William Ginter Riva — he was also an executive producer on the film.
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18. The Hobbit and Hannibal star Richard Armitage appeared as Heinz Kruger, the HYDRA assassin that killed Abraham Erskine, in Captain America: The First Avenger.
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19. Buffy the Vampire Slayer star Alexis Denisof played The Other in The Avengers and Guardians of the Galaxy.
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20. Wynonna Earp star Dominique Provost-Chalkley appeared as Zrinka, a woman in Sokovia who couldn't find her brother, in Avengers: Age of Ultron.
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21. Director Joe Russo made a brief cameo in Captain America: The Winter Soldier as Doctor Fine, a trusted surgeon who worked with S.H.I.E.L.D.
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22. Also, Joe made an appearance in Captain America: Civil War as Dr. Broussard, the psychiatrist that Helmut Zemo murdered and impersonated in order to get close to Bucky.
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23. Twin Peaks star Harry Dean Stanton appeared as a security guard who chatted with Bruce Banner in The Avengers.
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24. Homeland star Nazanin Boniadi played reporter Amira Ahmed in Iron Man.
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25. The Walking Dead star Ross Marquand appeared as Red Skull in Avengers: Infinity War — he took over the role from Hugo Weaving.
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26. Lost and Once Upon a Time star Rebecca Mader made an appearance in Iron Man 3 as an undercover agent for A.I.M.
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27. Logan Marshall-Green played Jackson Brice, a member of Adrian Toomes's criminal group, in Spider-Man: Homecoming.
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28. Fantastic Beasts: The Crimes of Grindelwald star Claudia Kim played Doctor Helen Cho, a geneticist that helped the Avengers in Avengers: Age of Ultron.
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29. Teen Wolf star Linden Ashby appeared in Iron Man 3 as a commander — alongside The Walking Dead's Corey Hawkins.
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30. Once Upon a Time star Josh Dallas originally portrayed Fandral in Thor — he was later replaced by Zachary Levi.
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31. Rage Against The Machine's Tom Morello appeared in Iron Man as a prison guard.
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32. The Haunting of Hill House star Mckenna Grace starred as young Carol Danvers in Captain Marvel.
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33. And of course, Luke Hemsworth and Matt Damon both appeared as actors playing Thor and Loki in Thor: Ragnarok.
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