Fort St. Angelo is a bastioned fort in Birgu, Malta, located at the centre of the Grand Harbour. It was originally built in the medieval period as a castle called the Castrum Maris. It was rebuilt by the Order of Saint John as a bastioned fort called Fort Saint Angelo between the 1530s and the 1560s, and it is best known for its role as the Order's headquarters during the Great Siege of Malta of 1565. A major reconstruction to designs of Carlos de Grunenbergh took place in the 1690s, giving the fort its current appearance.

Birgu, also known by its title Città Vittoriosa, is an old fortified city on the south side of the Grand Harbour in the South Eastern Region of Malta. The city occupies a promontory of land with Fort Saint Angelo at its head and the city of Cospicua at its base. Birgu is ideally situated for safe anchorage, and over time it has developed a very long history with maritime, mercantile and military activities.