The Olympic Games, or Olympics, are an international multi-sport event taking place every four years and comprising summer and winter games. Beginning in 776 BC, they were originally held in Olympia, Greece until 393 AD. In 1896, they were revived by a French nobleman, Pierre Frèdy, Baron de Coubertin, thus beginning the era of the Modern Olympic Games. The Summer Olympics (Games of the Olympiad) have been held every fourth year starting in 1896, except in 1916, 1940, and 1944 due to the World Wars. A special edition for winter sports, the Olympic Winter Games, was first held in 1924. The first winter Olympics competitions were held as a non-Olympic sports festival, but were declared to be official Games by the International Olympic Committee in 1925. Originally these were held in the same year as the Summer Olympics, but as of 1994 (the Lillehammer Games) the Winter Games and the Summer Games have been held two years apart.

There are many legends surrounding the origin of the ancient Olympic Games. One of these associates the first Games with the ancient Greek concept of εκεχειρία (ekecheiria) or Olympic Truce. The date of the Games inception based on the count of years in Olympiads is reconstructed as 776 BC, although scholars opinions diverge between dates as early as 884 BC and as late as 704 BC.

From then on, the Olympic Games quickly became much more important throughout ancient Greece, reaching their zenith in the sixth and fifth centuries BC. The Olympic Games were of fundamental religious importance, contests alternating with sacrifices and ceremonies honouring both Zeus (whose colossal statue stood at Olympia), and Pelops, divine hero and mythical king of Olympia famous for his legendary chariot race, in whose honour the games were held. The number of events increased to twenty, and the celebration was spread over several days. Winners of the events were greatly admired and were immortalised in poems and statues. The Games were held every four years, and the period between two celebrations became known as an Olympiad. The Greeks used Olympiads as one of their methods to count years. The most famous Olympic Games athlete lived in these times: the sixth century BC wrestler Milo of Croton is the only athlete in history to win a victory in six Olympics.

The Olympic Games gradually declined in importance as the Romans gained power in Greece. When Christianity became the official religion of the Roman Empire, the Olympic Games were seen as a pagan festival and in discord with Christian ethics, and in 393 CE the emperor Theodosius I outlawed the Olympics, ending a thousand-year tradition.