Bassiano (locally Vassiano) is a municipality (Italian: comune) in the Province of Latina in the Italian region Lazio, located about 60 kilometres (37 mi) southeast of Rome and about 14 kilometres (9 mi) northeast of Latina. As of 31 December 2004, it had a population of 1,664 and an area of 31.6 square kilometres (12.2 sq mi).

Its patron saint is Erasmus of Formia, and its church is named after him.

Bassiano borders the municipalities of Carpineto Romano, Norma, Sermoneta, Sezze.