(Χελιδονίς), a Spartan woman of great beauty and royal blood, daughter of Leotychides. She married Cleonymus, who was much older than herself, and to whom she proved unfaithful in consequence of a passion for Acrotatus, son of Areus I. It was partly on account of this injury that Cleonymus, offended also by his exclusion from the throne, invited Pyrrhus to attempt the conquest of Sparta in B. C. 272. Chelidonis, alarmed for the result, was prepared to put an end to her own life rather than fall into her husband's hands; but Pyrrhus was beaten off from the city, chiefly through the valour of Acrotatus. If we may trust the account of Plutarch, the Spartans generally of both sexes exhibited more sympathy with the lovers than indignation at their guilt,--a proof of the corruption of manners, which Phylarchus (apud Athen. iv. p. 142b.) ascribes principally to Acrotatus and his father. (Plut. Pyrrh. 26_28.)