The Holmenkollen 50 km is an annual cross-country skiing race held at Holmenkollen National Arena in Oslo, Norway. The competition is part of the Holmenkollen Ski Festival. Prior to 2023, the 50 km distance was raced by men only as the women's equivalent was a 30 km race. Since the 2023 edition, both men and women have raced 50k.

The first 50 km race in Oslo was planned to be part of Husebyrennet i 1887, but was first held in 1888. Torjus Hemmestveit won the inaugural 50 km race. 17 skiers started the race, 12 finished. The course consisted of two laps of 25 km and started at the velodrome at Majorstuen.

The next long-distance race, a 30 km, was planned to be part of Holmenkollrennene in 1898, but was cancelled due to lack of snow. 30 km races were held in 1900 and 1901, and the winners of these races are widely recognised as Holmenkollen 50 km winners. Also the winner of the 1907 edition is recognised as a winner, even though the course length was only 40 km. The first Holmenkollen 50 km race was held in 1902. The course consisted of two laps of 25 kilometres, both started and finished at Frognerseteren. For safety reasons, all skiers had to stop for a five-minute rest. These required pauses was only mandatory in the 1902 edition.

In 1905, the 50 km race was again cancelled due to lack of snow. Holmenkollrennene (later known as Holmenkollen Ski Festival) were in 1909 a part of a common arrangement with the first Norwegian Championships in cross-country skiing, and since a 30 km race was held at Lillehammer in these championships, the 50 km race in Holmenkollen was not held. The first foreign competitors at the Holmenkollen 50 km were a number of Swedes participating in 1903. The first non-Norwegian to win the race was Finnish skier Anton Collin in 1922. Tapani Niku, also from Finland, finished in second place.

In 1925 was the 50 km cancelled due to lack of snow in the days before Holmenkollrennene. Holmenkollrennene was threatened by lack of snow also in 1932, but was held two weeks after schedule. Holmenkollrennene, including the 50 km were not held during the Second World War.

Oslo arranged the World Championships in 1930, 1966, 1982 and 2011. In all the World Championships held in Oslo, the Holmenkollen 50 km was arranged as a part of the World Championships. In 1952, a separate 50 km race was held two weeks after the 1952 Winter Olympics in Oslo. The individual races in the 1982 World Championships were a part of the 1981–82 Cross-Country World Cup, the first official World Cup season, and the Holmenkollen 50 km race has since been a part of the World Cup, with the exception in 1985 when the 50 km did not have World Cup status. The cross-country skiing events at the 2011 World Championships were not part of the World Cup, unlike the 1982 World Championships.

In the 1985–86 season, cross-country skiing started to distinguish techniques and arrange separate races in classic style and freestyle (skating). The 50 km in Holmenkollen has since been arranged in both techniques. Lack of snow hindered the Holmenkollrennene again in 1990 and 1992, which caused the 50 km to be moved to Vang. Lillehammer hosted the 1994 Winter Olympics, and no 50 km race was held in Holmenkollen that year. The Holmenkollen National Arena was reconstructed in 2009 to prepare for the 2011 World Championships and the 50 km was therefore replaced by a World Cup race in Trondheim. Since 2010, the Holmenkollen 50 km has been competed with a mass start.

There was no race in 2021. It resumed the next year.