Castignano is a comune (municipality) in the Province of Ascoli Piceno in the Italian region Marche, located about 80 kilometres (50 mi) south of Ancona and about 10 kilometres (6 mi) northeast of Ascoli Piceno. As of 31 December 2004, it had a population of 3,039 and an area of 38.9 square kilometres (15.0 sq mi).