Oristano (in Sardinian: Aristanis) has approximately 32,000 inhabitants and is the capital of Oristano Province in west-central Sardinia.

The Gulf of Oristano is an inlet in the Sea of Sardinia, that part of the Mediterranean which lies between Sardinia and Spain’s Balearic Islands. It takes its name from the city of Oristano and is, together with the Gulf of Alghero, one of the major gulfs on the west coast of the island. It is bordered on the north by Cape San Marco on the Sinis Peninsula, and on the south by Cape Frasca; it washes the coasts of Oristano Province and, to the south, Medio Campidano. The Gulf lies off the coast of Oristano town and is bordered by mountainous promontories on either side, with flatter land in the middle.

The city of Oristano, was the home-town of Eleonora d’Arborea. She rules part of Sardinia from 1383 to 1404. She fought to keep the Spanish invaders and her greatest legacy “Carta de Logu” was one of the first Collection of Laws in the world. The centre of Oristano retains still part of his medieval origins.

Near the bay are numerous ponds, or stagni, including the Stagno di Cabras, the Stagno di Mystras and the Stagno di Santa Giusta, offering plentiful wildlife and many scenic areas of interest. The whole area can be considered a birdwatching hotspot.

The main activities of the Gulf area include fishing, fish farming and manufacturing activities connected with fishing, particularly the production of bottarga (a sort of caviar prepared from salted and cured grey mullet roe). Tourism is concentrated in the town of San Giovanni di Sinis, the Marina di Torre Grande, Putzu Idu, Is Benas and Lido di Arborea. Overlooking the gulf is the famous archaeological site of Tharros, and in the immediate vicinity of Oristano lies the mouth of the Tirso, the longest river in Sardinia.