Kapanen had a highly decorated international career with Finland in collecting a medal at every level played. He made his debut as a junior in the 1997 World Junior Championships, claiming a gold medal at the following junior Championships in 1998. At the senior men's level Kapanen competed in 9 World Championships in capturing 5 medals, including a gold at the 2011 World Championships. He twice represented Finland at the Winter Olympics claiming a Silver and Bronze at the 2006 and 2010 tournaments respectively.