Upcoming season or competition: 2025 World Junior Ice Hockey Championships | |
 | |
| Sport | Ice hockey |
|---|---|
| First season | 1974 (unofficial) 1977 (official) |
| No. of teams | 10 |
| Most recent champion(s) |  United States (6th title) (2024) |
| Most titles |  Canada (20 titles) |
| Relegation to | Division I Division II Division III |
| Official website | IIHF.com |
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 Sweden to win the 2024 edition in Gothenburg, Sweden.