- Chris Pratt Peter Quill / Star-Lord
- Zoe Saldana Gamora
- Dave Bautista Drax
- Vin Diesel Groot (voz)
- Bradley Cooper Rocket (voz)
- Will Poulter Adam Warlock
- Karen Gillan Nebula
- Pom Klementieff Mantis
- Sylvester Stallone Stakar Ogord
- Elizabeth Debicki Ayesha
- Sean Gunn Kraglin / On-Set Rocket
- Michael Rosenbaum Martinex