IIHF World Junior Championship

The IIHF World Junior Championship (WJC), sometimes referred to as World Juniors, is an annual event organized by the International Ice Hockey Federation (IIHF) for national under-20 ice hockey teams from around the world. It is traditionally held in late December, ending in early January (beginning from Boxing Day to January 5). The tournament usually attracts the top hockey players in this age category.

The main tournament features the top ten ranked hockey nations in the world, comprising the 'Top Division', from which a world champion is crowned. There are also three lower pools—Divisions I, II and III—that each play separate tournaments playing for the right to be promoted to a higher pool, or face relegation to a lower pool.

The competition's profile is particularly high in Canada, and this is partly for historical reasons because prior to NHL players being allowed in the Winter Olympics, this was a rare tournament where the best western players faced the best players from the Soviet Bloc, and the only other tournament of similar stature where this occurred was the irregularly scheduled Canada Cup for senior sides. The tournament's stature in Canada can also be credited to Canada's strong performance in the tournament (it has won the gold medal twenty times since its inception), the role of hockey in Canadian culture, along with strong media coverage and fan attendance. As such, in recent years, nearly half of the tournaments have been held in Canadian cities, with the remainder being held in Europe and the United States.

The United States is the defending champion, having defeated Finland to win the 2025 edition in Ottawa, Canada.

The first official tournament was held in 1977, although the first three tournaments were held unofficially from 1974 to 1976. The tournament has been dominated by the teams from Canada and Soviet Union/CIS/Russia, together accounting for 33 of the 49 overall gold medals awarded (through 2025). The USSR won the first four official tournaments, while the Canadians put together five straight championships between 1993 and 1997, and another five straight from 2005 to 2009. Canada leads the all-time gold medal count with 20 golds, while the Soviet Union, the CIS, and Russia combined have 13 golds.

When it began, the World Junior Championship was a relatively obscure tournament. It has since grown in prestige, particularly in Canada, where the tournament ranks as one of the most important events on the sports calendar and during the holiday season. The Globe and Mail writer Bruce Dowbiggin credits TSN, along with Canada's strong performance at the tournament, for turning it from an obscure non-event when it acquired the rights in 1991 (which had started to grow in prominence due to the 1987 Punch-up in Piestany) to one of Canada's most beloved annual sports events, and at the same time cementing the link between Canadian nationalism and hockey, and inspiring the NHL's Winter Classic. Based on increasing attendances for countries repeatedly hosting the event, the popularity of the tournament seems to be growing in other nations as well.

At editions of the tournament held in the country, games involving Team Canada consistently sell out NHL arenas, offering large profit guarantees to Hockey Canada and the IIHF. In the 21st century, Canada has and will continue to host the tournament every second or third year due to the significantly greater following the tournament has in Canada compared to other participating countries. Originally, Switzerland was selected to host the WJHC in 2010, but withdrew. Buffalo, New York, in the United States, hosted the tournament in 2011 and 2018; in both cases, proximity to Canada's population core in Southern Ontario was a key factor to the city winning the bidding rights.

The tournament offers one of the most prestigious stages for young hockey players, significantly boosting a player's value for upcoming NHL Entry Drafts.