Røyken is a district and village (bygd) and a former municipality in Buskerud in Viken County, Norway.

The municipality (originally the parish) is named after the old Røyken farm (Norse Raukvin), since the first church was built there.

The background for the motif is a common misunderstanding of the name as røyken the definite form of røyk meaning "smoke".

The main population centers are the villages of Hyggen, Hallenskog, Midtbygda, Nærsnes, Røyken, Slemmestad, Spikkestad, and Åros.

A tentative agreement was reached and on 16 June 2016 the Municipal Council of Røyken approved the merger with Asker and Hurum with 24 votes for and 3 against.