Bømlo is a municipality in Sunnhordland, in the southern part of the county of Hordaland, Norway. It is also the name of the main island of this archipelago, consisting of about 900 islets, located west of Stord.The old municipality of Finnås was divided into Bømlo, Bremnes, and Moster on 1 July 1916. The two latter municipalities were merged back into Bømlo on 1 January 1963.Bømlo was also involved in the Shetland bus operation in WWII.The municipality is named after the main island of Bømlo (Norse Bymbil). The meaning of the name is unknown (for a possible interpretation see under Bamble). Until 1918 the name was written Bømmel.