Need to know who plays who? Look no further! Here's the master list! This list contains ONLY characters who have been released and named openly. For actors who are on reserve for surprise characters / plot characters / yet to be released characters, see the Master Reserve List.
INTERNS
Cyle Jamison - Jeremy Sumpter (Commercial Recreation)
Malyk Lyonhart - Sean Faris (Sports Medicine)
Noah Beddinfield - Tobey Maguire (Bio - Pre-med)
Pheonix Kiser - Jim Sturgess (Bio - microbiology)
Rafael Aguilara - Cody Longo (Computer Engineering)
ORDER MEMBERS
Devyn Pelletier - Matt Long (History, Superior Studies)
Elijah Andreu - William Moseley (Philosophy, Superior Studies)
Lauren Sun - Lucy Liu
Vincent Renaud - Max Thieriot (CSN General Studies)
ROGUE SUPERIORS
Aiden Sloan - Michael Welch
Albert Grey - James McAvoy
Amber Schultz - Keri Russel
Anthony Phillips - Kevin G Schmidt
Cian Stuart - Hayden Christensen
Cortez Quintana - Nick Ayler
Denver Heartily - Mike Vogel
Elliot Webb - Jason Earles
Epsilon Montehough - Justin Bartha
Icarus Nailo - Adam Levine
Jason Banks - Matt Damon
Joey Bedivere - Nicky Byrne
Leonidus Josef Ferdinand Rudolf Habsburg-Lorraine - William Levy
Loki - Aaron Yoo
Mitchell "Roxas" Bellamy - Josh Hutcherson (Journalism)
Melody Rennell - Vanessa Hudgens
Mikel Presnor - Hal Sparks (Theatre)
Milo Thomas - Michael Angarino
Nicholas Bigsby - William Melling
Rhys Cholhagen - Kris Allan (Entertainment Engineering and Design)
Romulus - Karl Urban
Sanick Highwind - Ryan Cabrara (Music - Recording)
Tazz Gallahad - Matt Dallas (Superior Studies)
Tori Ferraro - Tory Belleci
NOMADS
Sean Oliver - Liam Neeson
HARVEST
Auron Marquis - Steven Strait
Sindel Borgia - Christina Scabbia
HUMANS
Ammon Nefers - Oded Fehr
Charles Thompson - Christian Bale
Edward Gates - Martin Sheen
Frank Lee - Mark Walhburg
Haroon Jaspal - Sacha Dhawan
Jamie Anderson - Robert Schwartzman
Jeremy Leiner - Cameron Bright
Rian Hannigan - Jesse McCartney
Robert Gallahad - Patrick Dempsey
Scott Matthews - Scott Mechlowitz
SUPERNATURAL BEINGS
Calder / Cancer - Josh Duhamel
Delia / Leo - Natalie Portman
Porcelain Queen - Hannah Fury
Poseidon - Sean Connery
Vekk - Himself
Verin - Max Irons
FAMILIES
Andre Demasi -
Angelo Romano - Adam Scott
Caine Peterson - Kingston Rossdale
Catalin Aguilara - Silvana Arias
Cody Leiner - Bradley Steven Perry
Elio Aguilara - David Deluise
Elizabeth Mathews - Allison Janney
Enrico Aldez - Raul Olivo
Esmerelda Aguilara - Rosario Dawson
Gloria Presnor - Sharon Gless
James Peterson - Adam Savage
Julie Jamison - Blythe Danner
Lucian Savage - J.B. Ghuman Jr.
Marcus Demasi - Tyler James Williams
Marcos Aguilara - David Henrie
Phillepe Pelletier - George Clooney
Samuel Mathews - Joshua Malina
DECEASED
Derrick Southerland - Dominic Monaghan
Ethan Schultz - Jake Abel
Jacob Fetcher - Shia LaBeouf
Jonathan Jamison - Matthew McConaughey
Shaw - Robert Shaw
William Latham - Stephen Lang