Sant'Andrea Frius (Sant'Andria ‘e Frius in Sardinian) is a comune (municipality) in the Province of South Sardinia in the Italian region Sardinia, located about 30 kilometres (19 mi) north of Cagliari.

Sant'Andrea Frius borders the following municipalities: Barrali, Dolianova, Donorì, Ortacesus, San Basilio, San Nicolò Gerrei, Senorbì, Serdiana.

The area of Sant'Andrea has been inhabited since prehistoric times, as testified by the presence of several nuraghi and other findings.

The settlement originated as a Phoenician stronghold, later conquered by the Romans, who had several villas here.

In 129 it was sold by Mariano II of Arborea to the Republic of Pisa, who held it until the Aragonese conquest in 1353.