The Battle of Fort Charlotte or the siege of Fort Charlotte was a two-week siege conducted by Spanish General Bernardo de Gálvez against the British fortifications guarding the port of Mobile (which was then in the British province of West Florida, and now in Alabama) during the Anglo-Spanish War of 1779-1783. Fort Charlotte was the last remaining British frontier post capable of threatening New Orleans in Spanish Louisiana. Its fall drove the British from the western reaches of West Florida and reduced the British military presence in West Florida to its capital, Pensacola.

Gálvez's army sailed from New Orleans aboard a small fleet of transports on January 28, 1780. On February 25, the Spaniards landed near Fort Charlotte. The outnumbered British garrison resisted stubbornly until Spanish bombardment breached the walls. The garrison commander, Captain Elias Durnford, had waited in vain for relief from Pensacola, but was forced to surrender. Their capitulation secured the western shore of Mobile Bay and opened the way for Spanish operations against Pensacola.