Mats Sundin got his start in professional ice hockey with Nacka HK of Hockeyettan, the third division of hockey in Sweden, during the 1988-89 season. The following year he joined Djurgårdens IF of the top league, even though he had been drafted in the 1989 National Hockey League draft by the Quebec Nordiques, becoming the first European number one draft in the league. Having won the Swedish League, he began skating with the Nordiques in 1990 and remained with them through 1994, before being traded to the Toronto Maple Leafs. First, however, he played with Djurgårdens due to the 1994–95 NHL lockout, but then spent 11 seasons with the Leafs, before a final year with the Vancouver Canucks in 2008-09.
Internationally, Sundin represented Sweden at the European Junior Championships in 1989 and 1990, winning the latter tournament. In the latter year, he also played in both the junior and senior World Championships, capturing silver in the latter. He then took gold at the Worlds in 1991 and 1992, before dropping to bronze in 1994. He won gold at the 1998 World Championships and also made his Olympic début that year, when Sweden was eliminated in the quarter-finals. He was third at the 2001 World Championships, but eliminated in the quarter-finals again at the 2002 Salt Lake City Olympics. After being runner-up at the 2003 World Championships, he finally captured Olympic gold in 2006. He was inducted into the Hockey Hall of Fame in 2012 and the International Ice Hockey Hall of Fame the following year. His number was retired by the Toronto Maple Leafs.