Bieber, 21, stood alongside the Canadian team and helped the games participants get pumped up during the first day of the nine-day event in Los Angeles, California, reported People magazine.
"Let's to Canada," Bieber Tweeted, sharing a video of himself chanting "Let's go Canada" with the athletes.
The "Baby" hitmaker, who was wearing a gingham shirt and straw fedora for the event at the Los Angeles Memorial Coliseum, also posed for photos with close friend Cody Simpson, 18, Maria Shriver, 59, and Maria Menounos, 37.