During his NHL rookie season, the Anaheim Ducks loaned Smith-Pelly to the Canadian junior team for the 2012 World Junior Championships. One of two players to be loaned from the NHL (Tampa Bay Lightning forward Brett Connolly was the other), he was named an alternate captain for the team. In Canada's first game of the tournament, against Finland, he broke a bone in his left foot blocking a shot. Opting to stay with the team rather than return to Anaheim to begin his rehabilitation, Smith-Pelly watched as Canada went on to win the bronze medal and since he was part of the Canadian roster, he also received a medal.