Sappho (; Greek: Σαπφώ Sapphō [sap.pʰɔ̌ː]; Aeolic Greek Ψάπφω Psápphō; c. 630 – c. 570 BC) was an Archaic Greek poet from Eresos or Mytilene on the island of Lesbos. Sappho is known for her lyric poetry, written to be sung while accompanied by music. In ancient times, Sappho was widely regarded as one of the greatest lyric poets and was given names such as the "Tenth Muse" and "The Poetess". Most of Sappho's poetry is now lost, and what is extant has mostly survived in fragmentary form; only the "Ode to Aphrodite" is certainly complete. As well as lyric poetry, ancient commentators claimed that Sappho wrote elegiac and iambic poetry. Three epigrams attributed to Sappho are extant, but these are actually Hellenistic imitations of Sappho's style.

Little is known of Sappho's life. She was from a wealthy family from Lesbos, though her parents' names are uncertain. Ancient sources say that she had three brothers; Charaxos (Χάραξος), Larichos (Λάριχος) and Eurygios (Εὐρύγιος). Two of them, Charaxos and Larichos, are also mentioned in the Brothers Poem discovered in 2014. She was exiled to Sicily around 600 BC, and may have continued to work until around 570 BC. According to legend, she killed herself by leaping from the Leucadian cliffs due to her love for the ferryman Phaon.

Sappho was a prolific poet, probably composing around 10,000 lines. Her poetry was well-known and greatly admired through much of antiquity, and she was among the canon of Nine Lyric Poets most highly esteemed by scholars of Hellenistic Alexandria. Sappho's poetry is still considered extraordinary and her works continue to influence other writers. Beyond her poetry, she is well known as a symbol of love and desire between women, with the English words sapphic and lesbian deriving from her name and that of her home island respectively.