The Great Siege of Gibraltar was an unsuccessful attempt by Spain and France to capture Gibraltar from the British during the American Revolutionary War. It was the largest battle in the war by number of combatants.

Gibraltar is a British Overseas Territory and city located at the southern tip of the Iberian Peninsula, on the Bay of Gibraltar, near the exit of the Mediterranean Sea into the Atlantic Ocean. It has an area of 6.7 km2 (2.6 sq mi) and is bordered to the north by Spain. The landscape is dominated by the Rock of Gibraltar, at the foot of which is a densely populated town area, home to some 32,688 people, primarily Gibraltarians.