The Dallas Buyers Club actor has joined the rumoured shortlist for Marvel Studios' film, reports Deadline.
Who should play Marvel's Doctor Strange? Cumberbatch, Laurie and more
Tom Hardy and Benedict Cumberbatch are also claimed to be in the running to play the sorcerer in Disney's entry into the magical side of the Marvel Comics universe.
Prometheus writer Jon Spaihts has entered talks to work on the Doctor Strange screenplay, which will be directed by Scott Derrickson.
Leto is also reported to be in talks to replace Will Smith in the science fiction movie Brilliance.
Created by Stan Lee and Steve Ditko in 1963, Doctor Stephen Strange was a talented but proud surgeon whose career was ended after an injury to his hands.
In seeking a cure for his injuries, he was inducted into the mystical arts and became the protector of Earth from supernatural forces.
A release date for the Doctor Strange film has yet to be announced.