Måsøy is a municipality in Finnmark county, Norway. The administrative centre of the municipality is the village of Havøysund.
Måsøy was established as a municipality on 1 January 1838 (see formannskapsdistrikt). The western part of the island of Magerøya was transferred from Måsøy to the municipality of Nordkapp on 1 January 1984.
The municipality is located on the coast of Western Finnmark, comprising parts of the mainland and many islands of various sizes. Most people live in the village of Havøysund, but there are also small hamlets spread around the islands and in the fjord areas, notably Snefjord, Kokelv, Ingøy, Rolvsøy, and Måsøy. The Fruholmen lighthouse is the northernmost in Norway.
The hurtigruten boat stops at Havøysund daily, and there is a road connection, albeit often blocked by snow in the winter.