- Robert Downey Jr. Tony Stark / Iron Man
- Chris Hemsworth Thor
- Mark Ruffalo Bruce Banner / Hulk
- Chris Evans Steve Rogers / Capitán América
- Scarlett Johansson Natasha Romanoff / La Viuda Negra
- Jeremy Renner Clint Barton / Ojo de Halcón
- Don Cheadle Coronel James 'Rhodey' Rhodes / War Machine
- Aaron Taylor-Johnson Pietro Maximoff / Quicksilver
- Elizabeth Olsen Wanda Maximoff / Bruja Escarlata
- Paul Bettany Jarvis / Visión
- Cobie Smulders Maria Hill
- Stellan Skarsgård Erik Selvig
- James Spader Ultrón (voz)
- Samuel L. Jackson Nick Furia
- Hayley Atwell Peggy Carter
- Thomas Kretschmann Baron Wolfgang von Strucker
- Andy Serkis Ulises Klaue
- Stan Lee Stan Lee
- Linda Cardellini Laura
- Idris Elba Heimdall
- Lou Ferrigno Hulk (voz)
- Claudia Kim Dr. Helen Cho
- Anthony Mackie Sam Wilson / Falcon
- Julie Delpy Madame B
- Henry Goodman Dr. List