The LP was crowned the country's coveted $30,000 award at a ceremony last night (September 24) at Toronto's Concert Hall.
The singer-songwriter beat Drake, Kathleen Edwards and seven other artists to win the top prize.
"Everyone had a favourite here tonight and I did too – and I did not think it was me," Feist said of her win.
Last year's winners Jeremy Gara and Tim Kingsbury of Arcade Fire presented Feist with the award.
She added: "I'm just really shocked and really grateful to be part of the night and I'll be going to all of these gigs. I want to see at least an hour and a half of all these people who played tonight."
The Polaris Prize voting process involves an 11-member jury that sit on throne chairs behind closed doors during a round table discussion about each album, before casting secret votes.
The overall winner is held secret - even from the grand jurors - until announced on stage.
Also nominated for the prize were Cold Specks, Cadence Weapon, Grimes, Handsome Furs, Japandroids and Yamantaka//Sonic Titan.
After her win, Feist said: "I was really moved by Cold Specks. I thought that was coming from as true a place as Grimes, but on some opposite polar ends of some meter that has yet to be invented. Each of them is doing something super unique."
Feist has previously won eight Juno Awards, and has been nominated for four Grammys and three Polaris Prizes.
Watch the video for Feist's 'The Bad in Each Other' below: