The night also saw CBC win another two awards, adding to 18 garnered during two ceremonies held earlier this week.
Sunday’s two-hour gala, hosted by comedian Andrea Martin and broadcast on CBC TV, was the culmination of week-long festivities in Toronto honouring the best in Canadian film, television and digital programming.
Mommy is about a widowed mother, Diane Després, struggling with the difficulty of raising her violent son. Both Anne Dorval, who plays Després, and Antoine Olivier Pilon, who plays her son Steve, took home awards for best actress and actor in a leading role.
Montreal-born director Xavier Dolan also took the best original screenplay award, as well as achievement in direction. The film, set in Montreal's South Shore neighbourhood, has garnered critical acclaim around the world and won the Jury Prize at the Cannes Film Festival last year.
Dolan dedicated the writing prize to his mother at a pre-show gala that took place before Andrea Martin took the stage to helm the star-studded telecast.
"It's too bad this is not on the air, I would have loved my mom to hear that," Dolan said to chuckles from the audience.
"I'd love to thank my mother and dedicate this award to her, I truly mean it. In spite of our differences she is the most absolute source of inspiration to me. And I don't call her as often as I should and we don't see each other as often as she'd wish but she should know."
Pompeii, a historical disaster film, also swept up five awards including achievement in art direction and visual effects.
Famed Hollywood director David Cronenbourg's satirical Hollywood drama Maps to the Stars nabbed two awards — original score and a best supporting actor win for John Cusack.
CBC wins another 2 trophies
On the smaller screen, CBC added another two to its awards haul — best actor to Jonas Chernick for his role in political satire The Best Laid Plans, and best sports host to Ron Maclean for Hockey Night in Canada.
Sunday’s accolades add to 18 awards garnered over the past week for CBC news, comedies, documentaries and sports programs.
TV fan favourite Orphan Black took home the prize for best dramatic series and best actress in a dramatic role for leading lady Tatiana Maslany. The popular series, which airs on Space, won a total of 10 trophies this year.
"It's such an honour to be here tonight," Maslany said as she claimed her trophy.
"I'm so lucky to have this job, I feel so so lucky.... [Thank you to] all of the writers on our show and the cast and crew who are tireless and who fight for integrity and artistry at every level. Thank you, thank you, I could not do this without you."
A big winner from previous years, Call Me Fitz, won two awards including best TV comedy series. Rounding out other major awards are The Amazing Race Canada for best reality series, and Bomb Girls: Facing the Enemy for best dramatic TV mini-series.
Earlier, host Martin kicked off the show with jabs at Canadian politeness and frigid temperatures, and shoutouts to famous faces in the audience, including friend Eugene Levy and recent Oscar-winner Julianne Moore.
"Let's give out some awards before they turn this place into a condo!" Martin declared, as the show launched in earnest from downtown Toronto's glass-encased opera house.
Orphan Black and Mommy led the nominees overall with 13 apiece.
Other winners during the non-televised portion of the gala included:- Achievement in Music - Original Score: Maps to the Stars
- Achievement in Music - Original Song: Dr. Cabbie
- Adapted Screenplay:Elephant Song
- Best Animated Short:Me and My Moulton
- Best Cinematography in a Feature Length Documentary: Everything Will Be
- Best Live Action Short Drama:Hole
- Best Short Documentary:Jutra
- Ted Rogers Best Feature Length Documentary: Super Duper Alice Cooper
- Best International Drama:Vikings
Below is a full list of winners from tonight's gala. On mobile? Click here to see the list.