The 59-square-kilometre (23 sq mi) municipality is the 409th largest by area out of the 422 municipalities in Norway. Sula is the 126th most populous municipality in Norway with a population of 9,007. The municipality's population density is 157.9 inhabitants per square kilometre (409/sq mi) and its population has increased by 19.5% over the last decade.
Originally, most of the island of Sula was part of the old Borgund Municipality and the small southwestern part of the island was part of Ulstein Municipality (see formannskapsdistrikt). On 1 July 1958, the southwestern part of Sula island was transferred to Borgund Municipality. In 1968, Borgund Municipality (including all of the island of Sula) was merged with the town of Ålesund to form the large Ålesund Municipality. On 1 January 1977, the entire island of Sula and the many small islets around it were separated from Ålesund Municipality to become a separate municipality. The initial population of the new Sula Municipality was 6,302.
The municipality is named after the island of Sula. The name is probably identical with the word sula which means "cleft", probably referring to the cleft between the twin peaks of Rundehornet and Vardane.
The coat-of-arms is from modern times; they were granted on 16 December 1983. The arms show a silver and blue figure which represents the cleft of the island.