Logan Lerman
Percy Jackson
Brandon T. Jackson
Grover Underwood
Alexandra Daddario
Annabeth Chase
Douglas Smith
Tyson
Leven Rambin
Clarisse La Rue
Jake Abel
Luke Castellan
Katelyn Mager
Young Thalia
Grey Damon
Chris Rodriguez
Paloma Kwiatkowski
Thalia Grace
Anthony Stewart Head
Chiron
Stanley Tucci
Mr. D / Dionysus
Nathan Fillion
Hermes
Robert Maillet
Polyphemus / Laistrygonian
Ron Perlman
Polyphemus (voice)
Connor Dunn
Tereus
Alisha Newton
Young Annabeth
Bjorn Yearwood
Young Grover
Samuel Braun
Young Luke
Mary Birdsong
Gray Sister #1
Yvette Nicole Brown
Gray Sister #2
Missi Pyle
Gray Sister #3
Octavia Spencer
Martha (voice)
Christopher Redman
Reardon
Jordan Weller
Ichneutae
Camille Atebe
Harpy Barista
Anthony Shim
Barista - Hecatonshire
Robert Knepper
Kronos
Richard Yearwood
Ganymede
Derek Mears
Cyclops #1
Aleks Paunovic
Cyclops #2
Maxine Miller
Parcel Store Customer
Shohreh Aghdashloo
Oracle (voice)
Craig Robinson
George (voice)