Tiomila or 10-mila is an orienteering race held annually in Sweden since 1945, usually in late April or early May. It is a 10-man relay which includes both night and daytime legs. The women's race consists of five daylight legs. Tiomila attracts club teams from all the major orienteering nations. In 2008, both the men's and the women's race consisted of about 350 teams. In 2019, there were 336 women's teams, and 310 men's teams.^[1]

The name means "ten mil" (100 km) and refers to the total distance run by each team. The actual distance, however, varies from year to year. The 2015 edition was measured to 116 kilometres (72 mi) along the straight line between the controls.

The following classes are available within Tiomila:

• 10-milakavlen (open class but in practice with mostly male runners) is carried out with ten legs between Saturday evening and Sunday morning, the original race since 1945.^[2] At the longest stage of the roll – the fourth stage's "Long Night", during the darkest part of the night – a night light is necessary to orientate in the terrain. The stretch often covers around 100 minutes of the men's heat's ten hours and was decided during the 2017 Ten Mile from just before midnight to around 1.30am.^[3] This year, this equated to almost 17 kilometers of cross-country running in the dark.^[4]

• Damkavlen (only ladies) is carried out with five legs on Saturday afternoon and was added in 1977. Over the years it has grown to approximately 400 participating teams.^[2]
• Ungdomskavlen (for young people 12-16 years old) is carried out with four sections (two of which consist of girls only) at lunchtime on Saturday. The competition was introduced in 1992.^[2]

These rules apply to competitors in Tiomila (in addition to the usual rules in orienteering):

• It is permitted for girls and boys who have run the youth race to participate in the 10-mile race. The girls are also allowed to participate in the female breeding.* Det är tillåtet för damer som sprungit damkavlen att delta i 10-milakavlen.
• It is not permitted to participate more than once in the same class.

• Jukola relay
• O-Ringen
• List of sporting events in Sweden