Cross-country skiing (also known as XC skiing) is a winter sport popular in many countries with large snowfields, primarily Northern Europe, Canada and Alaska. The popularity of the sport has been quickly growing in the United States and in Australia.

Cross-country skiing is part of the Nordic skiing sport family, which also includes ski jumping, and a combination sport of cross-country skiing and ski jumping called Nordic combined. Free-technique cross-country skiing is also the method of locomotion in the combination sport of Biathlon, which adds rifle marksmanship to skiing.

A hobby and a sport

"Bushwalking on skis" is a hobby where skiers tackle trails of various lengths and difficulties. Some skiers stay out for extended periods using tents and equipment similar to bushwalkers/hikers, whereas others take relatively short trips from ski resorts on maintained trails. In some countries, organizations maintain a network of huts for use by cross-country skiers in wintertime. For example, the Norwegian Mountain Touring Association maintains over 400 huts stretching across hundreds of kilometres of trails which are used by hikers in the summer and by skiers in the winter.

As a sport, cross-country skiing is one of the most difficult endurance sports, as its motions use every major muscle group and it (along with running, rowing and swimming) is one of the sports that burn the most calories per hour in execution. Modern cross-country ski competition is experiencing a revolution that is resulting in greater compatibility with audiences which began with the addition of the Sprint event to the World Cup and Olympic competitions. Today more and more races are being held in audience friendly formats, such as mass start, sprint, relay and pursuit (a race that involves switching skis and styles halfway through the race). The modern events in which athletes compete in at the World Cup and Olympics are (distances presented in Female/Male format): 1 km Sprint, 2X1 km Team Sprint, 10 km/15 km Individual Start, 15 km/30 km Pursuit, 30 km/50 km Mass Start, and 4x5 km/4x10 km Relay.

Sports events

The Winter Olympics, the FIS Nordic World Ski Championships, and the FIS World Cup events (including the Holmenkollen) have long been a showcase for the world's fastest cross country skiers. There are also special distance ski races, sometimes called ski marathons, like Vasaloppet in Sweden, Birkebeineren in Norway, the Canadian Birkebeiner and the American Birkebeiner and the Tug Hill Tourathon in the US. The skiing styles in these races might be fixed, or, in case of the so-called "double pursuit" event, the two styles are used each in their own separate half of the race (with a change of equipment in "pit stops" half way through).