The siege of San Fiorenzo was a British military operation, supported by Corsican partisans early in the French Revolutionary Wars against the French-held town of San Fiorenzo on the Mediterranean island of Corsica. The Corsican people had risen up against the French Republican garrison in 1793 after an attempt to arrest the Corsican leader Pasquale Paoli during the Reign of Terror. The French had then been driven into three fortified towns on the northern coast; San Fiorenzo, Calvi, and Bastia and Paoli appealed to the British Royal Navy's Mediterranean Fleet, commanded by Lord Hood, for assistance against the French garrison.

The French Revolutionary Wars were a series of sweeping military conflicts resulting from the French Revolution that lasted from 1792 until 1802. They pitted France against Great Britain, Austria, Prussia, Russia, and several other countries. The wars are divided into two periods: the War of the First Coalition (1792–1797) and the War of the Second Coalition (1798–1802). Initially confined to Europe, the fighting gradually assumed a global dimension. After a decade of constant warfare and aggressive diplomacy, France had conquered territories in the Italian Peninsula, the Low Countries and the Rhineland. French success in these conflicts ensured the spread of revolutionary principles over much of Europe.