Robert Downey Jr. (Tony Stark / Iron Man), Chris Evans (Steve Rogers / Captain America), Samuel L. Jackson (Nick Fury), Mark Ruffalo (Bruce Banner / The Hulk), Chris Hemsworth (Thor), Scarlett Johansson (Natasha Romanoff / Black Widow), Jeremy Renner (Clint Barton / Hawkeye), Tom Hiddleston (Loki), Clark Gregg (Agent Phil Coulson), Cobie Smulders (Agent Maria Hill), Stellan Skarsgård (Selvig), Gwyneth Paltrow (Pepper Potts), Paul Bettany (Jarvis), Alexis Denisof (Der Andere), Tina Benko (NASA-Wissenschaftlerin), Jerzy Skolimowski (Georgi Luchkov), M'laah Kaur Singh (junges Mädchen), Powers Boothe (Weltsicherheitsrat), Jenny Agutter (Weltsicherheitsrat), Arthur Darbinyan (Weltsicherheitsrat), Donald Li (Weltsicherheitsrat), Maximiliano Hernandez (Agent Jasper Sitwell), Harry Dean Stanton (Wachmann), Ashley Johnson (Kellnerin), Robert Clohessy (Polizist), Enver Gjokaj (junger Polizist)