Bassiano (locally Vassiano) is a municipality (Italian: comune) in the Province of Latina in the Italian region Lazio, located about southeast of Rome and about northeast of Latina. As of 31 December 2004, it had a population of 1,664 and an area of .
Its patron saint is Erasmus of Formia, and its church is named after him.
Bassiano borders the municipalities of Carpineto Romano, Norma, Sermoneta, Sezze.