Biathlon is a term used to describe any sporting event made up of two disciplines. However, biathlon usually refers specifically to the winter sport that combines cross-country skiing and rifle shooting. Other popular variants include summer biathlon, which combines cross-country running with riflery, modern biathlon and biathle, which combine running with swimming.

The sport has its origins in an exercise for Norwegian soldiers, as an alternative training for the military. One of the world's first known ski clubs, the Trysil Rifle and Ski Club, was formed in Norway in 1861 to promote national defense at the local level.

Called military patrol, the combination of skiing and shooting was contested at the Olympic Winter Games in 1924, and then demonstrated in 1928, 1936, and 1948, but did not regain Olympic recognition then, as the small number of competing countries disagreed on the rules (see also Governing body, below). During the mid-1950s, however, biathlon was introduced into the Soviet and Swedish winter sport circuits and was widely enjoyed by the public. This newfound popularity aided the effort of having biathlon gain entry into the Winter Olympics.