Slemmestad is a village in Røyken municipality, Norway. Slemmestad is located on the Oslofjord, west of Oslo, Norway. Historically Slemmestad was located on the old highway running between from Oslo and Drammen. Until the establishment of cement factory in 1888, this was a pure farming village. The largest farms were the Lillelien, together with øvre and nedre Slemmestad. Slemmestad was built around the Aktieselskabet Christiania Portland Cementfabrik cement plant. Aktieselskabet Christiania Portland Cementfabrik, later Slemmestad sementfabrikk, was in operation from 1893 to 1989. The company was for many years the principal manufacturer of cement within Norway. The factory was rebuilt several times with new and more modern cement kilns. Cement production peaked in 1973 when it produced 1,082,677 tons.