The Thirties-set film, which is already generating Oscar buzz among film pundits, tells the tale of John Halder, a German professor whose morals are tested after a book he has penned gets favourable attention from the Nazis. Jason plays support to Viggo Mortensen as his Jewish best friend Maurice.
This week's unveiling of the film, which was also attended by Jason's British co-star Jodie Whittaker, marked the fruition of a long term project for Jason. Although he began work on it in 2005, the production stalled due to funding issues and the departure of original leading man Hugh Jackman, who left to do X-Men 3.
Jason and co weren't the only ones launching new films at the Canadian festival this week. Oscar-winner Adrien Brody and Mark Ruffalo were also there, along with Rachel Weisz, for the premiere of adventure comedy The Brothers Bloom.
Paris Hilton was in town, too, accompanied by musician boyfriend Benji Madden. The Tinseltown socialite hosted her own party for festival goers at hip Toronto hangout The Ultra Supper Club.