Castellar was a comune (municipality) in the Province of Cuneo in the Italian region Piedmont, located about southwest of Turin and about northwest of Cuneo. As of 31 December 2004, it had a population of 253 and an area of .
Castellar was an autonomous comune up to the end of 2018; on 1 January 2019 it was united to the neighbouring comune of Saluzzo, thus enforcing the results of a referendum held in the summer of 2018.
The comune of Castellar bordered the following municipalities: Pagno, Revello, and Saluzzo. It had the following frazioni: Regione Giardino, Regione Morra, Regione Pairunella, Regione San Guglielmo, Regione Testa Nera