Hadrian's Villa (Italian: Villa Adriana; Latin: Villa Hadriana) is a UNESCO World Heritage Site comprising the ruins and archaeological remains of a large villa complex built around AD 120 by Roman emperor Hadrian near Tivoli outside Rome.

It is the most imposing and complex Roman villa known. The complex contains over 30 monumental and scenic buildings arranged on a series of artificial esplanades at different heights and surrounded by gardens decorated with water basins and nymphaea (fountains). The whole complex covers an area of at least a square kilometre, an area larger than the city of Pompeii. In addition to the villa's impressive layout, many of the buildings are considered masterpieces of Roman architecture, making use of striking curved shapes enabled by extensive use of concrete. They were ingenious for the complex symmetry of their ground plans and are considered unrivalled until the arrival of Baroque architecture in the 17th century, initiated by Borromini, who used Hadrian's Villa for inspiration.

The site, much of which is still unexcavated, is owned by the Republic of Italy and has been managed since 2014 by the Polo Museale del Lazio.