2018 World Junior Ice Hockey Championships

The 2018 World Junior Ice Hockey Championship was the 42nd edition of the Ice Hockey World Junior Championship, and was hosted by the city of Buffalo, New York  at KeyBank Center and HarborCenter. It opened on December 26, 2017 and closed with the gold medal game on January 5, 2018. It was the sixth time that the United States has hosted the WJIHC, and the second time that Buffalo has done so, previously hosting in 2011.

A preliminary round game between Canada and the United States was played outdoors at New Era Field in nearby Orchard Park, New York on December 29, 2017. It was the second outdoor game held at any top-level IIHF world championship, the first being the opening game of the 2010 IIHF World Championship, and the first one held at a junior level.

Host selection
On July 28, 2015, USA Hockey named the five initial finalists for hosting the event:
 * Buffalo, New York
 * Pittsburgh
 * St. Louis
 * Chicago
 * Tampa, Florida

Chicago and Tampa were eliminated on September 15. Buffalo was chosen as the host site on December 3, with a formal announcement on December 4.

Match officials
The following officials were assigned by the International Ice Hockey Federation to officiate the 2018 World Junior Championship.

Referees
 * Andris Ansons
 * 🇨🇦 Alexandre Garon
 * Jacob Grumsen
 * 🇫🇮 Mikko Kaukokari
 * 🇷🇺 Artur Kulev
 * 🇦🇹 Manuel Nikolic
 * 🇩🇪 Gordon Schukies
 * 🇨🇿 Robin Šír
 * 🇸🇪 Mikael Sjöqvist
 * 🇺🇸 Stephen Thomson
 * 🇺🇸 Jeremy Tufts
 * Marc Wiegand

Linesmen
 * Franco Castelli
 * 🇫🇮 Markus Hägerström
 * 🇺🇸 William Hancock II
 * Rene Jensen
 * 🇳🇴 Jon Kilian
 * 🇨🇦 Dustin McCrank
 * 🇨🇿 Jiří Ondráček
 * 🇸🇰 Peter Šefčík
 * 🇷🇺 Alexander Sysuev
 * 🇸🇪 Emil Yletyinen

Format
The preliminary round was a two group of five teams each internal round-robin format, followed by a three-round playoff. In the round-robin, two points were allotted for a win, and one additional point for a regulation win. One point was allotted for an overtime or game winning shots loss.

The four highest-ranked teams from each group of the preliminary round advanced to quarterfinals while the last-placed team from each group played a best-of-three series, the loser relegated to Division IA for 2019. All other teams will retain their Top Division status.

Preliminary round
''All times are local. (Eastern Standard Time – UTC-5)''

Relegation round
Note: 🇧🇾 was relegated to the 2019 Division I A

Scoring leaders
Source: IIHF

Goaltending leaders
(minimum 40% team's total ice time)

Source: IIHF

Tournament awards
Most Valuable Player

🇺🇸 Casey Mittelstadt

All-star team
 * Goaltender: 🇸🇪 Filip Gustavsson
 * Defencemen: 🇸🇪 Rasmus Dahlin, 🇨🇦 Cale Makar
 * Forwards: 🇺🇸 Casey Mittelstadt, 🇨🇿 Filip Zadina, 🇺🇸 Kieffer Bellows

IIHF best player awards
 * Goaltender: 🇸🇪 Filip Gustavsson
 * Defenceman: 🇸🇪 Rasmus Dahlin
 * Forward: 🇺🇸 Casey Mittelstadt

Division I A
The Division I A tournament was played in Courchevel and Méribel, France, from December 10 to 16, 2017.

Division I B
The Division I B tournament was played in Bled, Slovenia, from December 9 to 15, 2017.

Division II A
The Division II A tournament was played in Dumfries, United Kingdom, from December 10 to 16, 2017.

Division II B
The Division II B tournament was played in Belgrade, Serbia, from January 10 to 16, 2018.

Main tournament
The Division III main tournament was played in Sofia, Bulgaria, from January 22 to 28, 2018.

Qualification
The Division III qualification tournament was played in Cape Town, South Africa, from February 5 to 7, 2018.