Otrere or Otrera (ancient Greek Ὀτρήρη Otrḗrē) was in Greek mythology a queen of the Amazons.
She was the mistress of the Olympian god of war Ares and by him the mother of Penthesilea, sporadically Hippolyte is also mentioned as her daughter, who elsewhere was accidentally killed by Penthesilea. Usually she appeared as the sole ruler of the Amazons, but is also mentioned together with her daughter Antiope as the ruler of a dual kingship. Otrere was considered to be the queen of the Amazons.
Otrere was considered to have built the temple of Artemis at Ephesus (near present-day Selçuk on the southwest coast of Turkey), or, together with Antiope, to have built a temple to Ares, which they erected when they went out to war.