Villa of Domitian, Roman archaeological site in Castel Gandolfo, Italy

Villa of Domitian is a Roman archaeological site in the Alban Hills featuring remains of palaces, baths, and water systems spread across multiple levels. The complex includes traces of nymphaeums, underground passages, and sophisticated piping that once supplied the entire estate.

A Roman emperor built this summer retreat in the late 1st century as an escape from his duties. The site lay abandoned for centuries before archaeologists began uncovering its underground structures.

Domitian practised archery at the villa, as Suetonius records, and Pliny suggests he held boating parties on Lake Albano. Martial names the estate among the emperor's favoured resorts. The name Albanum Caesari, used for the imperial estate here, came from the concentration of villas around Alba Longa, the legendary Latin capital.

The ruins lie mostly inside the papal Villa Barberini estate at Castel Gandolfo, whose gardens are open to visitors; the rest falls in Castel Gandolfo and Albano Laziale. The remains were never fully excavated, so there is no complete plan and paths are informal. Giuseppe Lugli's surveys of 1913–1922 remain the basis for locating the structures.

The villa's marbles were reused in the 14th century to build and clad the Cathedral of Orvieto. In 1321 the Savelli lords allowed its structures to be dismantled, a demolition that lasted 36 days. Giuseppe Lugli made the first archaeological survey of the site from the airship "Roma" in 1919, with Thomas Ashby of the British School of Rome aboard.