Sam Worthington as Perseus

Gemma Arterton as Io

Mads Mikkelsen as Draco

Alexa Davalos as Andromeda

Jason Flemyng as Calibos / Acrisius

Ralph Fiennes as Hades

Liam Neeson as Zeus

Pete Postlethwaite as Spyros

Polly Walker as Cassiopeia

Ashraf Barhom as Ozal

Elizabeth McGovern as Marmara

Nicholas Hoult as Eusebios

Liam Cunningham as Solon

Hans Matheson as Ixas

Vincent Regan as Kepheus

Alexander Siddig as Hermes

Luke Treadaway as Prokopion

Mouloud Achour as Kucuk

Tine Stapelfeldt as Danae

Luke Evans as Apollo

Izabella Miko as Athena

Ian Whyte as Sheikh Sulieman

Katherine Loeppky as Aged Cassiopeia

Sinead Michael as Tekla

Ross Mullan as Pemphredo

Robin Berry as Enyo

Graham Hughes as Deino

Martin McCann as Phaedrus

Rory McCann as Bello

Kaya Scodelario as Peshet

Tamer Hassan as Ares

Danny Huston as Poseidon

William Houston as Ammon

Jamie Sives as Captain

Phil McKee as Harbourmaster

Geoffrey Beevers as Noble (Basilica)

Michael Grady-Hall as Citizen (Argos)

Laura Kachergus as Citizen (Argos)

Adrian Bouchet as Soldier (Zeus Statue)

David Kennedy as Kepheus' General

Nina Young as Hera

Jane March as Hestia

Nathalie Cox as Artemis

Agyness Deyn as Aphrodite

Natalia Vodianova as Medusa

Charlotte Comer as Demeter

Louis Leterrier as Kraken (uncredited)

Katrina Vasilieva as Exotic Dancer (uncredited)