Simonides of Ceos (; Ancient Greek: Σιμωνίδης ὁ Κεῖος; c. 556 – 468 BC) was a Greek lyric poet, born in Ioulis on Ceos. The scholars of Hellenistic Alexandria included him in the canonical list of the nine lyric poets esteemed by them as worthy of critical study. Included on this list were Bacchylides, his nephew, and Pindar, reputedly a bitter rival, both of whom benefited from his innovative approach to lyric poetry. Simonides, however, was more involved than either in the major events and with the personalities of their times.
Lessing, writing in the Enlightenment era, referred to him as "the Greek Voltaire." His general renown owes much to traditional accounts of his colourful life, as one of the wisest of men; as a greedy miser; as an inventor of a system of mnemonics; and the inventor of some letters of the Greek alphabet (ω, η, ξ, ψ). Such accounts include fanciful elements, yet he had a real influence on the sophistic enlightenment of the Classical era. His fame as a poet rests largely on his ability to present basic human situations with affecting simplicity. In the words of the Roman rhetorician Quintilian (35–100 AD):