Accepting his award for International Video of the Year by a Canadian from his girlfriend and the show's host, Selena Gomez, Bieber joked: "Selena, nice to meet you, I'm Justin. You're very beautiful. Maybe we can go out sometime?" The 17-year-old singer also won Favorite Artist.
Gaga, who performed twice during Sunday night's show, won Favorite International Video for "Born this Way" and International Video of the Year for "Judas."
Canada's MuchMusic Video Awards were broadcast live from Toronto on Fuse in the U.S. See the full list of winners here.