The fortifications of Valletta (Maltese: Is-Swar tal-Belt Valletta) are a series of defensive walls and other fortifications which surround Valletta, the capital city of Malta. The first fortification to be built was Fort Saint Elmo in 1552, but the fortifications of the city proper began to be built in 1566 when it was founded by Grand Master Jean de Valette. Modifications were made throughout the following centuries, with the last major addition being Fort Lascaris which was completed in 1856. Most of the fortifications remain largely intact today.

The city of Valletta, along with Nicosia in Cyprus, was considered to be a practical example of an ideal city of the Renaissance, and this was due to its fortifications as well as the urban life within the city. The fortifications were well known throughout Europe by the 17th century, and might have influenced the designs of part of the Fortress of Luxembourg. In an 1878 book, Valletta was described as "one of the best fortified [cities] in the world." Valletta's fortifications are the most important of the fortifications of Malta, and are now part of a UNESCO World Heritage Site.