In Greek mythology, Hilaera (; also Ilaeira) was a daughter of Leucippus and Philodice. She and her sister Phoebe are commonly referred to as Leucippides (that is, "daughters of Leucippus").
Hilaera and Phoebe were priestesses of Artemis and Athena, and betrothed to Lynceus and Idas, the sons of Aphareus. Castor and Pollux were charmed by their beauty and carried them off. When Idas and Lynceus tried to rescue their brides-to-be they were both slain, but Castor himself fell. Pollux persuaded Zeus to allow him to share his immortality with his brother.
Hilaera married Castor and bore him a son, named either Anogon or Anaxis.
Hilaera and Phoebe are both portrayed in The Rape of the Daughters of Leucippus painting.