Arzachena (Italian pronunciation: [artsaˈkɛːna]; Gallurese: Alzachèna; Sardinian: Altzaghèna) is a town and comune in the province of Sassari, northern Sardinia, the second largest island off the coast of Italy.

Nearby there are numerous archaeological sites from the Nuragic period, including those from a local sub-culture known as Arzachena culture (the necropolis of Li Muri and others).

Located in an area once inhabited by the Arzachena culture, the region was known by the Romans as Turibulum, after a mushroom-shaped rock which is today the symbol of the town.

The oldest recorded use of the modern name is in a 1421 document, when king Alfonso IV of Aragon gave it (under the spelling Arsaghene) as a fief to Ramboldo de Cobaria.

In 1909 the new village had 853 inhabitants, a population which grew substantially after the tourist boom associated with Costa Smeralda, which had originally been a small stretch of coast in the commune of Arzachena.