Aglientu is a town and comune located in the Province of Gallura in the north-east region of Sardinia, an autonomous island region in Italy. Geographically, it is situated approximately 210 kilometres (130 mi) north of Cagliari and about 35 kilometres (22 mi) northwest of Olbia.
The municipality has a population of 1,195 inhabitants. It serves as a local administrative center within the Gallura province of northern Sardinia.