Ice hockey is played on a large flat area of ice, using a three inch (76.2 mm) diameter vulcanized rubber disc called a puck. This puck is often frozen before high-level games to decrease the amount of bouncing and friction on the ice. The game is contested between two teams of skaters. The game is played all over North America, Europe and in many other countries around the world to varying extent. It is the most popular sport in Canada, Finland, Latvia, the Czech Republic, and in Slovakia.

The governing body of international play is the 66-member International Ice Hockey Federation (IIHF). Men's ice hockey has been played at the Winter Olympics since 1924, and was in the 1920 Summer Olympics. Women's ice hockey was added to the Winter Olympics in 1998. North America's National Hockey League (NHL) is the strongest professional ice hockey league, drawing top ice hockey players from around the globe. The NHL rules are slightly different from those used in Olympic ice hockey: the periods are 20 minutes long, counting downwards. There are three periods.

Ice hockey sticks are long L-shaped sticks made of wood, graphite, or composites with a blade at the bottom that can lie flat on the playing surface when the stick is held upright and can curve either way, legally, as to help a left- or right-handed player gain an advantage.

There are early representations and reports of ice hockey-type games being played on ice in the Netherlands, and reports from Canada from the beginning of the nineteenth century, but the modern game was initially organized by students at McGill University, Montreal in 1875 who, by two years later, codified the first set of ice hockey rules and organized the first teams.

Ice hockey is played at a number of levels, by all ages.

The National Hockey League (French: Ligue nationale de hockey—LNH), often abbreviated to the NHL, is an unincorporated not-for-profit association, which operates a major professional ice hockey league of 30 franchised member clubs, of which six are located in Canada and 24 in the United States. Headquartered in New York City, the NHL is widely considered to be the premier professional ice hockey league in the world, and one of the major professional sports leagues of the United States and Canada. The Stanley Cup, the oldest professional sports trophy in North America, is awarded annually to the league playoff champion at the end of each season.

The league was organized in 1917 in Montreal, Canada after the suspension of operations of its predecessor organization, the National Hockey Association (NHA), which had been founded in 1909. It started with four teams and, through a series of expansions, contractions, and relocations; the league is now composed of 30 active franchises. After a "lockout" that led to the cancellation of the entire 2004–05 seasons, the league resumed play under a new collective bargaining agreement that included a salary cap. In 2009, the NHL enjoyed record highs in terms of sponsorships, crowds and television audiences.

The NHL draws many highly skilled players from all over the world and currently has players from about 20 different countries. Although Canadians have historically constituted the majority of the players in the NHL, over the past four plus decades the percentages of American and European trained players have increased both because of the NHL's continued expansion from six to thirty clubs since 1967, and the increased availability of highly skilled European players, especially from former Eastern Bloc countries.