Pietro da Castello was an armourer active in Brescia during the late fifteenth century. He is documented there between 1469 and 1486, and died sometime before 1498. His mark has been identified as a split cross straddling the letter P. This mark is found combined with a crown mark, as on the sallet in the 'Corinthian' style now in the Metropolitan Museum of Art in New York (inv. no. 14.25.579) or with the mark of the Lion of St. Mark, as on Wallace Collection A75.