2010 World Junior Ice Hockey Championships

The 2010 IIHF World U20 Championship, commonly referred to as the 2010 World Junior Hockey Championships (2010 WJHC), was the 34th edition of World Junior Ice Hockey Championships. The tournament was hosted in Saskatoon and Regina, Saskatchewan, Canada, from December 26, 2009, to January 5, 2010. This was the second time Saskatoon has hosted the tournament, after hosting it in 1991. The medal round, as well as all Canada's preliminary round games, took place in Saskatoon at the Credit Union Centre. The arena underwent renovations and upgrades before the 2010 tournament, including an increase in capacity. Other games were played at the Brandt Centre in Regina, which also received upgrades. In addition, pre-tournament exhibition games were held in other towns and cities throughout the province as well as Calgary, Alberta. In the gold medal match, the United States defeated the pre-tournament favourites and host country Canada 6–5 in overtime to win their second gold medal and first since 2004, ending Canada's bid for a record-breaking sixth consecutive gold medal.

Top division
The lowest-ranked teams in the top division are relegated to Division I for the following year's tournament.

Preliminary round
Ten teams were divided into two groups of five, each of which play in a single round-robin format. The winner of each group proceeded directly to the tournament semifinals, with the second- and third-place finishers advancing to the quarterfinals. The remaining four teams participated in the relegation round to determine which teams will be relegated to Division I the following year.

Group A
All times local (CST/UTC-6)

Group B
All times local (CST/UTC-6)

Relegation round
Results from any games that were played during the preliminary round were carried forward to the relegation round.

All times local (CST/UTC-6)

 and were relegated to Division I for the 2011 World Junior Ice Hockey Championships.

Division I
The following teams took part in the Division I tournament. Group A played in Megève and Saint-Gervais, France, between December 14 and December 20, 2009. Group B played in Gdańsk, Poland, between December 14 and December 20, 2009:

Group A
 was promoted to the Top Division and was relegated to Division II for the 2011 World Junior Ice Hockey Championships.

Group B
 was promoted to the Top Division and was relegated to Division II for the 2011 World Junior Ice Hockey Championships.

Division III
The tournament took place in Istanbul, Turkey, from January 4 to January 10, 2010. and have gained promotion to Division II for the 2011 IIHF World U20 Championship.