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)