Themistoclea
Themistoclea was a priestess at the Temple of Apollo at Delphi; the priestesses were mentors and tutors to many ancient Greek philosophers.
Themistoclea was Pythagoras’ teacher, teaching him moral doctrines, according to Diogenes Laërtius’s 3rd-century biography of Pythagoras in Lives and Opinions of Eminent Philosophers.
Porphyry (233–305 CE) calls her Aristoclea (Aristokleia), although he is presumed to be talking about the same person. He states “(Pythagoras) taught much else, which he claimed to have learned from Aristoclea at Delphi.”