The Vow actress could be starring in a role originally meant for Zooey Deschanel if a deal is concluded, according to The Hollywood Reporter.
McAdams is in talks to star as the female lead in the romantic comedy movie from British filmmaker Richard Curtis in a role reminiscent of her part in The Time Traveller's Wife.
The Love Actually director also wrote the script for About Time, which is about a man and his ability to travel back in time and eventually meets his ideal woman.
Domhnall Gleeson - best known to international audiences for his role as Bill Weasley in the Harry Potter movies - is already attached to the project.
Production on About Time is due to begin in London next month.
McAdams's future projects include Most Wanted Man, a thriller that Anton Corbijn is attached to direct.
She next will appear alongside Ben Affleck, Javier Bardem, Jessica Chastain, Michael Sheen and Rachel Weisz in an untitled project from director Terrence Malick.
Watch Channing Tatum and Rachel McAdams talking to Digital Spy about The Vow below: