Sardinian or Sard (sardu [ˈsaɾdu] / sadru [ˈsadɾu], limba sarda [ˈlimba ˈzaɾda] or lìngua sarda [ˈliŋɡu.a ˈzaɾda]) is a Romance language spoken by the Sardinians on the Western Mediterranean island of Sardinia.

Many Romance linguists consider it the language that, together with Italian, is closest to Latin among all the genealogical descendants of Latin.[12][13] However, it has also incorporated elements of a Pre-Latin (mostly Paleo-Sardinian and, to a much lesser degree, Punic) substratum,[14] as well as a Byzantine Greek, Catalan, Spanish and Italian superstratum. These elements of the language originate in the political history of the island of Sardinia: before the Middle Ages, it was for a time a Byzantine possession; then, after a significant period of self-rule with the judicates, it came during the late Middle Ages into the Iberian sphere of influence; and finally, from the 18th century onward, under the Italian one.

In 1997, Sardinian, along with other languages spoken on the island, was recognized by regional law as an official language of Sardinia,[3] and in 1999, Sardinian and eleven other minoranze linguistiche storiche ("historical linguistic minorities") were similarly recognized by national law (specifically, Law No. 482/1999).[15] Among these, Sardinian is notable as having the largest number of speakers.[16][17][18][19]

However, the number of native speakers has been declining, threatening the vitality of the Sardinian-speaking community.[20] While it was estimated in 2007 that 68.4 percent of the inhabitants of Sardinia had a good oral command of Sardinian,[21] most of them were past retirement age. Only 13 percent of children were reported to have this level of competence in the language,[22][23] with Sardinian being kept as a heritage language.[24][25] UNESCO has classified the language as "definitely endangered".[26]