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.

The fortifications of Birgu are a series of defensive walls and other fortifications which surround the city of Birgu, Malta. The first fortification to be built was Fort Saint Angelo in the Middle Ages, and the majority of the fortifications were built between the 16th and 18th centuries by the Order of Saint John. Most of the fortifications remain largely intact today.