Wilusa, (Hittite: ? URUwi5-lu-?a) or Wilusiya, was a major city of the late Bronze Age in western Anatolia. It was described in 13th century BC Hittite sources as being part of a confederation named Assuwa.
The city is often identified with the Troy of the Ancient Greek Epic Cycle. Many modern archaeologists have suggested that Wilusa corresponds to an archaeological site in Turkey known as Troy VIIa, which was destroyed circa 1190 BC. Ilios and Ilion (, ), which are alternate names for Troy in the Ancient Greek language, are linked etymologically to Wilusa. This identification by modern scholars has been influenced by the Chronicon (a chronology of mythical and Ancient Greece) written circa 380 AD by Eusebius Sophronius Hieronymus (also known as Saint Jerome). In addition, the modern Biga Peninsula, on which Troy VIIa is located, is now generally believed to correspond to both the Hittite placename Tarui?a and the Troas or Troad of late antiquity.
Not all scholars have accepted the identification of Wilusa with Troy. There is an alternative hypothesis, for example, that Wilusa was located near Beycesultan, which was known in the Byzantine era as "Iluza" ().
Wilusa per se is known from six references in Hittite sources, including: