Sigismondo Polcastro (1384–1473) was an Italian physician and natural philosopher. He was born to a jurist father, Girolamo, of the ancient de Porcastris family of Vicenza, and Maddalena Volpe of Padua. Perhaps born in Vicenza, he moved to Padua while he was still a boy.
He received a doctorate in arts from the University of Padua in 1412, taught natural philosophy from 1419, obtained a doctorate in medicine in 1424, and taught medicine from 1426 to 1464 or 1465. He wrote several short medical works.[1]
In 2016, he was pronounced the progenitor of the largest group of mathematicians in the Mathematics Genealogy Project, which groups mathematicians by teacher–student mentoring relationships, via his student Pietro Roccabonella.