is a municipality in Møre og Romsdal county, Norway. It is part of the Sunnmøre region of Western Norway. The administrative centre of the municipality is the village of Ørsta. Other villages in the municipality include Hovdebygda, Flåskjer, Liadal, Urke, Barstadvik, Åmdalen, Follestaddalen, Nordre Vartdal, Vartdal, Sæbø, Sætre, Store-Standal, and Ytre Standal.
The 662 km2 municipality is the 171st largest by area out of the 356 municipalities in Norway. Ørsta is the 105th most populous municipality in Norway with a population of 10,833. The municipality's population density is 16.7 PD/km2 and its population has increased by 4.2% over the previous 10-year period.
The municipality of Ørsta was established on 1 August 1883 when it was separated from Volda Municipality. The initial population was 2,070. On 1 January 1893, the Ytrestølen farm (population: 13) was transferred from Ørsta to Volda. During the 1960s, there were many municipal mergers across Norway due to the work of the Schei Committee. On 1 January 1964, the municipality of Ørsta (population: 6,209) was merged with the neighboring municipalities of Hjørundfjord (population: 1,728) and Vartdal (population: 1,315) to form a new, larger municipality of Ørsta. On 1 January 2020, the Bjørke and Leira areas of Ørsta were transferred to the neighboring Volda Municipality.