Ventotene, in Roman times known as Pandataria or Pandateria from the Greek Pandoteira, is one of the Pontine Islands in the Tyrrhenian Sea, 25 nautical miles (46 km) off the coast of Gaeta right at the border between Lazio and Campania, Italy. The municipality of Ventotene, of the province of Latina (Lazio) has 708 permanent residents as of 2008.

The island, the remains of an ancient volcano, is elongated, with a length of 3 kilometres and a maximum width of about 800 metres.

The municipality includes the small ancillary island of Santo Stefano, located 2 kilometres to the east, which is the site of a massive prison, now closed. A further island, Ponza, is 40 kilometres to the west.

The island is connected by ferry and hydrofoil service to Formia and Anzio; this is supplemented by summer services from and to Ischia.

Pandataria is best known as the island to which the emperor Augustus banished his daughter Julia the Elder in 2 BC, as reaction to her excessive adultery, where she was to spend five years, and to which Tiberius banished his grandniece Agrippina the Elder in 29 AD. She perished, probably of malnutrition, on October 18, 33 AD. After Agrippina's son Gaius (better known as Caligula) became emperor in 37 AD, he went to Pandataria to collect her remains and reverently brought them back to Rome. Agrippina's youngest daughter, Julia Livilla was also exiled to Pandateria twice: the first time by her brother Caligula for plotting to depose him and the next time by her uncle, the emperor Claudius, at the instigation of his wife, Messalina, in 41 AD. Sometime later, she was discreetly starved to death there and her remains were probably brought back to Rome when her sister Agrippina the Younger became influential as the emperor's wife. Another distinguished lady of the Julio-Claudian dynasty, Claudia Octavia, who was the first wife of the emperor Nero, was banished to Pandateria in 62 AD and executed on the orders of her husband.