A Illa de Arousa (Galician: [a ˈiʎɐ ð(e) aˈɾowsɐ]; unofficial Spanish: Isla de Arosa) is the only island municipality in Galicia, Spain in the province of Pontevedra.

The population is divided into several neighborhoods, and places of interest are the lighthouse's environment, the island of Areoso (close to the Illa de Arousa) and Carreirón Natural Park, which is listed as a special protection zone for heron populations among other birds that inhabit the island.

"San Xulián da Illa de Arousa" is the only parish in this island.

Some of its beaches are A Area da Secada, A Lavanqueira, O Vao, Camaxe, Carreirón, Espiñeiro and O Cabodeiro.

According to E. Bascuas, "Arousa", registered as insulam Arauza in 899, would belong to the old European hydronymy, and is derived from the Indo-European root *er- 'flow, move'.