Sant'Anna Arresi (Arresi in the Sardinian language) is a comune (municipality) in the Province of South Sardinia in the Italian region of Sardinia, located about 45 kilometres (28 mi) southwest of Cagliari and about 20 kilometres (12 mi) southeast of Carbonia.

The frazione of Porto Pino has a spotless beach that stretches for almost 2 kilometres (1.2 mi) with dunes that can reach as high as 29 metres (95 ft).

As its name suggests, the importance of this area from a naturalistic point of view comes from the presence of the Aleppo pine, which is present in a dense wood of about 90 hectares (220 acres).

There are also rare kermes oaks, which, in their bushy state, are found only in very few places on the island.

Ai confini tra Sardegna e Jazz is an international music festival.