List of IIHF World Under-20 Championship medalists

The IIHF World Junior Championship is an annual event organized by the International Ice Hockey Federation for national under-20 ice hockey teams from around the world. It is traditionally held from late December to the beginning of January. 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 with the last place team facing relegation to a lower pool.

The first official tournament was held in 1977. Prior to that, there had been invitational tournaments in 1974, 1975 and 1976 that were not sanctioned by the IIHF.

As of 2019, 43 official tournaments have been staged. Six nations have won a gold medal and ten have won medals. Historically, the tournament has been dominated by Canada (18 gold medals) and the Soviet Union / CIS / Russia (13 gold medals). 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 18 golds, while the Soviet Union/CIS/Russia have 13 golds. In the 2010s the competition has become more level with the United States and Finland each winning three and Canada winning two gold medals. Russia and Sweden also remained competitive winning one gold each.

Medalists
The winners by season listed below.

Official tournaments

 * Key
 * (#) Number of tournaments (or 2nd placed/3rd places) won at the time.

Medal table
The unofficial tournaments held prior to 1977 are not included in this table.

Countries in italics no longer compete at the World Championships.