Chris Pratt 
 as Peter Quill

Zoe Saldaña 
 as Gamora

Dave Bautista 
 as Drax

Vin Diesel 
 as Groot (voice)

Bradley Cooper 
 as Rocket (voice)

Lee Pace 
 as Ronan

Michael Rooker 
 as Yondu Udonta

Karen Gillan 
 as Nebula

Djimon Hounsou 
 as Korath

John C. Reilly 
 as Corpsman Dey

Glenn Close 
 as Nova Prime

Benicio del Toro 
 as The Collector

Laura Haddock 
 as Meredith Quill

Sean Gunn 
 as Kraglin / On Set Rocket

Peter Serafinowicz 
 as Denarian Saal

Christopher Fairbank 
 as The Broker

Krystian Godlewski 
 as On Set Groot

Wyatt Oleff 
 as Young Quill

Gregg Henry 
 as Grandpa

Janis Ahern 
 as Meredith's Mother

Solomon Mousley 
 as Meredith's Brother

Lindsay Morton 
 as Meredith's Best Friend

Robert Firth 
 as Dr. Fitzgibbon

Melia Kreiling 
 as Bereet

Tom Proctor 
 as Horuz

Nick Holmes 
 as Horuz' Mate

Max Wrottesley 
 as Sacrificed Nova Corpsman

Stan Lee 
 as Xandarian Ladies' Man

Nicole Alexandra Shipley 
 as Pretty Xandarian

Sharif Atkins 
 as Nova Arresting Pilot

Brendan Fehr 
 as Corpsman Dey's Partner

Tomas Arana 
 as Kree Ambassador

Mikaela Hoover 
 as Nova Prime's Assistant

Emmett Scanlan 
 as Head Riot Guard

Dominic Grant 
 as Angry Guard

Spencer Wilding 
 as Mean Guard

Alison Lintott 
 as Sad Woman with Horns

Alexis Rodney 
 as Moloka Dar

Nathan Fillion 
 as Monstrous Inmate

Keeley Forsyth 
 as Mottled Prisoner

Frank Gilhooley 
 as Burly Prisoner

Alexis Denisof 
 as The Other

Enzo Cilenti 
 as Watchtower Guard

Richard Katz 
 as One Legged Prisoner

Ene Frost 
 as Rifle Guard

Ronan Summers 
 as 'Drop the Leg' Guard

Ophelia Lovibond 
 as Carina

Laura Ortiz 
 as Tortured Pink Girl

Marama Corlett 
 as Pit Boss

Rosie Jones 
 as Lady of the Boot of Jemiah

Abidemi Sobande 
 as Lady of the Boot of Jemiah

Ekaterina Zalitko 
 as Lady of the Boot of Jemiah

Emily Redding 
 as Lady of the Boot of Jemiah

Stephen Blackehart 
 as Knowhere Dispatcher

Jennifer Moylan-Taylor 
 as Sad Krylorian Girl

Bruce Mackinnon 
 as One-Eyed Ravager

Ralph Ineson 
 as Ravager Pilot

Rob Zombie 
 as Ravager Navigator (voice)

Naomi Ryan 
 as Nova Centurion

John Brotherton 
 as Nova Starblaster Pilot

Graham Shiels 
 as Alien Nova Pilot

James Gunn 
 as Maskless Sakaaran

Douglas Robson 
 as Maskless Sakaaran

Rachel Cullen 
 as Corpsman Dey's Wife

Isabella Poynton 
 as Corpsman Dey's Daughter

Imogen Poynton 
 as Corpsman Dey's Daughter

David Yarovesky 
 as Goth Ravager

Miriam Lucia 
 as Crying Xandarian Citizen

Josh Brolin 
 as Thanos (uncredited)

Lloyd Kaufman 
 as Prisoner (uncredited)

Tyler Bates 
 as Ravager Pilot (uncredited)

Seth Green 
 as Howard the Duck (voice) (uncredited)

Jozef Aoki 
 as Kyln Prisoner (uncredited)

Erica Melargo 
 as Xandar Resident (uncredited)