The series - a prequel to classic Alfred Hitchcock horror Psycho - will star Freddie Highmore as a young Norman Bates and Vera Farmiga as his mother Norma.
Tracy will play Norman's teacher Miss Watson on the ten-episode series, Deadline reports.
The 40-year-old actress is best known for her role in 2003 film Final Destination 2 and for guest stints on shows such as Stargate SG-1, Battlestar Galactica and Supernatural.
Bates Motel previously cast Nestor Carbonell (The Dark Knight, Ringer), Mike Vogel (Pan Am) and British actress Olivia Cooke (Blackout).
The show is being run by former Lost producer Carlton Cuse, who is also developing comic adaptation The Sixth Gun for NBC.
> Psycho TV prequel Bates Motel will be 'edgy, provocative'
> Lost exec Carlton Cuse on Psycho TV prequel: 'Mrs Bates is hot'
Watch the trailer for Hitchcock below: