Castellaro (Ligurian: Castellâ) is a comune (municipality) in the Province of Imperia in the Italian region Liguria, located about 100 kilometres (62 mi) southwest of Genoa and about 14 kilometres (9 mi) west of Imperia. As of 31 December 2004, it had a population of 1,083 and an area of 8.7 square kilometres (3.4 sq mi).

Castellaro borders the following municipalities: Pietrabruna, Pompeiana, Riva Ligure, and Taggia.

Demographic evolution