Hemsedal is a municipality in Buskerud county, Norway. It is part of the traditional region of Hallingdal. The administrative centre of the municipality is the village of Trøym. Hemsedal lies on the Norwegian National Road 52. Hemsedal is located 220 km (136.70 mi) northwest of Oslo and 273 km (169.63 mi) from Bergen. In 1897, Hemsedal was separated from the municipality of Gol to become a municipality of its own.

Buskerud is a county and a current electoral district in Norway, bordering Akershus, Oslo, Innlandet, Vestland, Telemark and Vestfold. The region extends from the Oslofjord and Drammensfjorden in the southeast to Hardangervidda mountain range in the northwest. The county administration was in modern times located in Drammen. Buskerud was merged with Akershus and Østfold into the newly created Viken County on 1 January 2020. On 23 February 2022, the Viken County Council voted in a 49 against 38 decision to submit an application to the Norwegian government for a county demerger. Due to this, Buskerud was re-established in 2024.