The Republic of Genoa (Italian: Repubblica di Genova; Ligurian: Repúbrica de Zêna [ɾeˈpybɾika de ˈzeːna]; Latin: Res Publica Ianuensis) was an independent state and maritime republic from the 11th century to 1797 in Liguria on the northwestern Italian coast, incorporating Corsica from 1347 to 1768, and numerous other territories throughout the Mediterranean and the Black Sea.

Known as "la Superba" ("the Superb one"), "la Dominante" ("The Dominant one"), "la Dominante dei mari" ("the Dominant of the Seas"), and "la Repubblica dei magnifici" ("the Republic of the Magnificents"). From the 11th century to 1528 it was officially known as the "Compagna Communis Ianuensis" and from 1580 as the "Serenissima ("Most Serene") Republic of Genoa".

During the late Middle Ages, the Republic of Genoa was a major commercial power in the Mediterranean and Black Sea, while between the 16th and 17th centuries it was one of the major financial centers in Europe.

It was a celebrated maritime republic and today its coat of arms is depicted in the flag of the Italian Navy. In 1284, Genoa fought victoriously against the Republic of Pisa in the battle of Meloria for the dominance over the Tyrrhenian Sea, and it was an eternal rival of Venice for dominance in the Mediterranean Sea.

From 1339 until the state's extinction in 1797 the ruler of the republic was the Doge, originally elected for life, after 1528 was elected for terms of two years. However, in actuality, the Republic was in fact an oligarchy ruled by a small group of merchant families, from whom the doges were selected.

The republic began when Genoa became a self-governing commune in the 11th century and ended when it was conquered by the French First Republic under Napoleon and replaced with the Ligurian Republic. The Ligurian Republic was annexed by the First French Empire in 1805; its restoration was briefly proclaimed in 1814 following the defeat of Napoleon, but it was ultimately annexed by the Kingdom of Sardinia in 1815.