Cross-country skiing (also known as XC skiing) is a winter sport popular in many countries with large snowfields.

Ski touring is a form of backcountry skiing (off-piste skiing) involving travelling over the winter landscape on skis under human power rather than through the use of ski lifts or snow vehicles. Ski touring has parallels with hiking, backpacking, and mountaineering.

As a hobby, cross-country skiing may be viewed as a kind of "bushwalking on skis", 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.

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 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.