Sardinia, Kingdom of, a former Italian kingdom founded in the 18th century. In the 19th century, it was the leading state in the Italian unification movement and was largely instrumental in creating the Kingdom of Italy.

The Kingdom of Sardinia was formed in 1720 when Victor Amadeus, duke of Savoy, acquired the island of Sardinia from Austria and combined it with Savoy, Nice, and Piedmont in a monarchy. During 1792–93 the French occupied and annexed Savoy and Nice. Sardinia regained Nice in 1814 and Savoy in the following year, at the Congress of Vienna. While Sardinia retained its independence, the conferees in Vienna placed the other states of northern Italy under Austrian sovereignty.

Sardinian kings Charles Albert (reigned 1831–49) and Victor Emmanuel II (1849–61) were leaders in the fight to rid Italy of foreign rule and to create a unified nation. A revolution began in 1859. Victor Emmanuel ceded Savoy and Nice to Napoleon III in 1860 for his support. Both the Austrians and the Spanish were expelled from Italy. The Italian states were annexed to Sardinia and the enlarged domain in 1861 became the new Kingdom of Italy, with Victor Emmanuel II as monarch.