Swainbost (Scottish Gaelic: Suaineabost) is a village on the Isle of Lewis in the district of Ness, in the Outer Hebrides, Scotland. The name Swainbost meaning Sweins steading is of Viking derivation. The settlement is situated in the parish of Barvas. The remains of the church of Saint Peter, Teampull Pheadair, are located north of the settlement. The building was the parish church of Ness, and became a ruin in 1829. At the shore, there is a large depression called Suaineabost Sands which displays glacier activities and is run through by a river.