Sappho 31 is an archaic Greek lyric poem by the ancient Greek poet Sappho of the island of Lesbos. The poem is also known as phainetai moi after the opening words of its first line. It is one of Sappho's most famous poems, describing her love for a young woman.

Sappho 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 formerly attributed to Sappho are extant, but these are actually Hellenistic imitations of Sappho's style.