Cast of Legion

Dan Stevens portrays David Haller, also known as Legion, a troubled mutant with immense psychic powers.

Rachel Keller plays Sydney 'Syd' Barrett, a mutant with the ability to swap bodies through physical contact.

Aubrey Plaza takes on the role of Lenny Busker, David's friend who faces a dark and twisted journey.

Jeremie Harris appears as Ptonomy Wallace, a mutant with the skill to navigate through others' memories.

Amber Midthunder is Kerry Loudermilk, a mutant who shares a body with Cary and appears for physical combat.

Bill Irwin plays Cary Loudermilk, a brilliant scientist and a mutant cohabitating with Kerry in the same body.

Jean Smart represents Melanie Bird, a demanding therapist leading a group of mutants in the fight against Division 3.

Mackenzie Gray embodies The Eye, a mysterious and powerful pursuer affiliated with Division 3.

Katie Aselton plays Amy Haller, the adoptive sister of David, who seeks to protect her brother.

Hamish Linklater is Clark Debussy, an interrogator and agent of Division 3 with a special interest in mutants.

Lauren Tsai portrays Jia-Yi, also known as Switch, a young mutant with time-traveling abilities.

Navid Negahban plays Amahl Farouk, the enigmatic Shadow King who battles David for supremacy.