The Three Cities (Maltese: It-Tlett Ibliet) is a collective description of the three fortified cities of Vittoriosa, Senglea and Cospicua in Malta. The oldest of the Three Cities is Vittoriosa, which has existed since prior to the Middle Ages. The other two cities, Senglea and Cospicua, were both founded by the Order of Saint John in the 16th and 17th centuries. The Three Cities are enclosed by the Cottonera Lines, along with several other fortifications. The term Cottonera (Maltese: Il-Kottonera) is synonymous with the Three Cities, although it is sometimes taken to also include the nearby town of Kalkara.

Vittoriosa has been settled since the time of the Phoenicians, but the current city dates back from the time of the Order of Saint John. Vittoriosa was chosen as the capital city of Malta instead of Mdina upon the arrival of the Order in 1530. After the 1551 attack, Senglea was built on the peninsula known as L'Isola. In Vittoriosa, Fort Saint Angelo was built on the site of the ancient Castrum Maris, and Fort Saint Michael was built on Senglea.

The cities were besieged during the Great Siege of Malta of 1565, and after the siege was lifted Vittoriosa was given the title of Città Vittoriosa and Senglea the title of Città Invicta. In the aftermath of the siege, the city of Valletta was built, and in 1571 the new city became the capital instead of Vittoriosa. The cities' fortifications were strengthened during the reign of Grandmaster Nicolas Cotoner, and in 1722, Grandmaster Marc'Antonio Zondadari gave the town of Bormla the title of Città Cospicua.

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