Polycrates (, Polykratēs) may refer to:
Persons Polycrates, tyrant of Samos from c. 538 BC to 522 BC Polycrates (sophist) (c. 440-370 BC), author of paradoxical encomia and an Accusation of Socrates Polycrates of Ephesus (fl. c. AD 130-196), bishop Polycrates of Argos, the governor of Cyprus under the Ptolemy V Epiphanes.
Other Dalla polycrates, a butterfly in the family Hesperiidae Der Ring des Polykrates (poem), a lyrical ballad written in 1797