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.
2. Olivia Munn played a TV reporter at the Stark Expo in Iron Man 2.
3. Ty Burrell starred as Leonard, Bruce Banner's friend and Betty's original love interest, in The Incredible Hulk.
4. Miley Cyrus voiced Mainframe, a member of Stakar Ogord's team of Ravagers in Guardians of the Galaxy Vol. 2.
5. Before starring in Crazy Rich Asians, Michelle Yeoh appeared in Guardians of the Galaxy Vol. 2 as Aleta Ogord, a Ravager captain.
6. Happy Endings star Adam Pally played Gary, a cameraman who met Tony Stark in Iron Man 3.
7. Kate Mara appeared as a US marshal in Iron Man 2.
8. Comedian Garrett Morris made a cameo in Ant-Man as a cab driver — He famously parodied Ant-Man on Saturday Night Live.
9. Doctor Who star Jenna Coleman appeared as Bucky's date to the Stark Expo in Captain America: The First Avenger.
10. Community star Danny Pudi played a communications tech agent at S.H.I.E.L.D. in Captain America: The Winter Soldier.
11. Nathan Fillion voiced the monstrous inmate that teased Peter Quill in Guardians of the Galaxy.
12. Seth Green had a blink-and-you'll-miss-it cameo as a fan at the Stark Expo in Iron Man 2.
13. Also, Seth voiced Howard the Duck in Guardians of the Galaxy Vol. 1 and Vol. 2.
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.
15. Lou Ferrigno, who played The Hulk on the '90s TV series, appeared as a security guard in The Incredible Hulk.
16. Chris O'Dowd appeared as Richard, a guy who tried to date Jane, in Thor: The Dark World.
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.
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.
19. Buffy the Vampire Slayer star Alexis Denisof played The Other in The Avengers and Guardians of the Galaxy.
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.
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.
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.
23. Twin Peaks star Harry Dean Stanton appeared as a security guard who chatted with Bruce Banner in The Avengers.
24. Homeland star Nazanin Boniadi played reporter Amira Ahmed in Iron Man.
25. The Walking Dead star Ross Marquand appeared as Red Skull in Avengers: Infinity War — he took over the role from Hugo Weaving.
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.
27. Logan Marshall-Green played Jackson Brice, a member of Adrian Toomes's criminal group, in Spider-Man: Homecoming.
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.
29. Teen Wolf star Linden Ashby appeared in Iron Man 3 as a commander — alongside The Walking Dead's Corey Hawkins.
