Houtskär is an island group and a former municipality of Finland, located in the Southwest Finland region. It consists of a cluster of islands rather than a single continuous landmass.
On 1 January 2009, Houtskär ceased to be an independent municipality when it was consolidated with Iniö, Korpo, Nagu and Pargas to form the municipality of Pargas. Before that merger, it bordered the municipalities of Brändö, Iniö, Kökar, Korpo and Sottunga.
Its status as an island group and its position within the Archipelago Sea area of Southwest Finland are its defining geographical characteristics. Since 2009 it has formed part of the larger municipality of Pargas rather than functioning as a separate administrative unit.