Onias (Hebrew: חוֹנִיּוֹ Honio, also Honiyya or Honiyahu) was the name of several Jewish high priests at the time of the Second Temple, described by such sources as Josephus:
- Onias I, son of Jaddua and high priest in the late 4th and early 3rd century BCE
- Onias II, son of Simon the Just and probably grandson of Onias I, high priest in the early 2nd century BCE
- Onias III, son of Simon II and high priest in the early 2nd century BCE, came into conflict with the Seleucid government, was replaced by his brother and later murdered
- Menelaus (High Priest), who according to Josephus was originally called Onias, second successor and murderer of Onias III. An extreme hellenizer, Meneleus despoiled the Temple in Jerusalem and whose actions helped spark the Maccabee revolt
- Onias IV, son of Onias III who founded a Jewish Temple at Leontopolis in Egypt
Onias can also refer to:
- The Land of Onias, an area in Ptolemaic Egypt named after Onias IV that was heavily settled by Jews
- Honi ha-Magel, a 1st century BCE Jewish mystic mentioned in a number of midrashim and in the Talmud
- Alpha Onias III, a planet in the Star Trek: The Next Generation episode "Future Imperfect"