Harry has represented Denmark in four World Junior Championships. He played lead for Rasmus Stjerne in 2007 and 2008, finishing fourth and seventh, respectively. In 2009, Denmark, with Harry as lead under Stjerne, made the playoffs. They were defeated by Canada in the page 1 vs. 2 game, but rebounded with a win over the United States in the semifinal and defeated Canada in the final to win the gold medal. Harry played at the lead position under Mikkel Krause at the 2010 World Junior Curling Championships, but finished in eight place.