Sassari (Thatari in sardinian language), a town and a province in Sardinia, Italy.

The second town of the island by population, (est.120,000 inh.), Sassari is one of the ancient sardinian towns, and hosts perhaps the better collections of art of the island.

Its university has a relevant reputation, specially for jurisprudence studies, and in its bibliotheques are collected the most ancient documents, among which the famous Carta de Logu, the constitution issued by Giudichessa Eleonora d'Arborea, or the Condaghes, first codes and first documents written in Sardinian language (11th century). During the Catalan domination the city was named Sāsser.

Sassari is also the birthplace of many famous Sardinian people: among all the former president of the Italian Republic, sen. Francesco Cossiga, his cousin Enrico Berlinguer, for many years in the 1970s the national secretary and leader of the most important Communist party of western Europe, and their common uncle Antonio Segni, another former president of the Italian Republic.