Pietro da Siena (died 1500) was a high ranking Borgia guard in Rome and Captain of one of the five Borgia towers that ruled over the Centro District.


In 1500, Ezio Auditore da Firenze, during his quest to liberate Rome from the Borgia rule, killed Pietro and burned down the tower he resided in. Subsequently, the surrounding region was freed from Borgia oppression.

Two of Pietro's brothers, Prospero and Valentino, were also captains employed by the Borgia family.