Castoldi may refer to:
Business Castoldi (company), a French automobile manufacturing company Baldini & Castoldi, an Italian publishing house People Mario Castoldi (1888-1968), an Italian aeronautical engineer and aircraft designer Pietro Antonio Crespi Castoldi (1557 - 1615), Italian historian and Catholic priest Ray Castoldi (b. ?), an American organist noted for playing at sports events