Theaetetus (Θεαίτητος) is a Greek name which may refer to:Theaetetus (mathematician), Greek geometer Theaetetus (dialogue), a dialogue by Plato, named after the geometer Theaetetus (crater), a lunar impact crater Theaetetus (poet), Greek poet Theaetetus of Cyrene, Greek poet Theaetetus Scholasticus, Greek poet