- The main characters are Ikaris, Sersi, Eros, Druig and Margo Damien.
- Alexander Skarsgard, Charlie Hunnan and Sam Heughan are the frontrunners for Ikaris, the male lead.
- Sofia Boutella and Eiza Gonzalez are the frontrunners for Sersi, the female lead.
- Luke Evans and Matt Bomer are the frontrunners for Eros, the secondary male lead.
- Gina Rodriguez, Naomi Scott and Nathalie Emmanuel are the frontrunners for Margo, the secondary female lead.
- Colin Farrell and Keanu Reeves is the frontrunners for Druig, the lead antagonist.
- Supporting characters include Sprite, Thena, Elysius, Makkari, Gilgamesh, Zuras and Kro.
- Cailee Spaeny is the top choice for Sprite.
- Sylvia Hoeks is the top choice for Thena.
- Eva Green and Lena Headey are the top choices for Elysius.
- Rami Malek, Oscar Isaac and Pedro Pascal are the top choices for Makkari.
- Kevin Durand, Nonso Anozie, David Denman, DeObia Oparei and Hafþór Björnsson, among others, are being eyed for Gilgamesh.
- Liam Neeson, Ian McShane, Bernard Hill and Sean Bean, among others, are being eyed for Zuras.
- David Oyelowo, Mark Strong and Ralph Fiennes are being eyed for Kro.