Utsira is a municipality in Rogaland county, Norway. It is part of the traditional district of Haugaland. Utsira was separated from Torvastad on 1 July 1924.The municipality consists of an island located in the North Sea, 18 km west of Haugesund. Utsira is the smallest municipality of Norway in population and the second smallest in area (after Kvitsøy).
The Old Norse forms of the name was just Síri (nominative) and Síra (genitive). The first element ut (meaning "out" or "offshore": compare the "Out Skerries" in Shetland) was added in the 16th Century. (Sira is also the name of the border river between Rogaland and Vest-Agder.) The inhabitants still call the island just Sira and an inhabitant is called a sirabu. The meaning of the name Sira is unknown (maybe "strong stream").