Poetry (from the Greek word poiesis, "making") is a form of literary art that uses aesthetic and often rhythmic qualities of language to evoke meanings in addition to, or in place of, literal or surface-level meanings. Any particular instance of poetry is called a poem and is written by a poet. Poets use a variety of techniques called poetic devices, such as assonance, alliteration, consonance, euphony and cacophony, onomatopoeia, rhythm (via metre), rhyme schemes (patterns in the type and placement of a phoneme group) and sound symbolism, to produce musical or other artistic effects. They also frequently organize these devices into poetic structures, which may be strict or loose, conventional or invented by the poet. Poetic structures vary dramatically by language and cultural convention, but they often rely on rhythmic metre: patterns of syllable stress or syllable (or mora) weight. They may also use repeating patterns of phonemes, phoneme groups, tones, words, or entire phrases. Poetic structures may even be semantic (e.g. the volta required in a Petrachan sonnet).

Most written poems are formatted in verse: a series or stack of lines on a page, which follow the poetic structure. For this reason, verse has also become a synonym (a metonym) for poetry. Some poetry types are unique to particular cultures and genres and respond to characteristics of the language in which the poet writes. Readers accustomed to identifying poetry with Dante, Goethe, Mickiewicz, or Rumi may think of it as written in lines based on rhyme and regular meter. There are, however, traditions, such as Biblical poetry and alliterative verse, that use other means to create rhythm and euphony. Other traditions, such as Somali poetry, rely on complex systems of alliteration and metre independent of writing and have been described as structurally comparable to ancient Greek and medieval European oral verse. Much modern poetry reflects a critique of poetic tradition, testing the principle of euphony itself or altogether forgoing rhyme or set rhythm. In first-person poems, the lyrics are spoken by an "I", a character who may be termed the speaker, distinct from the poet (the author). Thus if, for example, a poem asserts, "I killed my enemy in Reno", it is the speaker, not the poet, who is the killer (unless this "confession" is a form of metaphor which needs to be considered in closer context – via close reading).

Poetry uses forms and conventions to suggest differential interpretations of words, or to evoke emotive responses. The use of ambiguity, symbolism, irony, and other stylistic elements of poetic diction often leaves a poem open to multiple interpretations. Similarly, figures of speech such as metaphor, simile, and metonymy establish a resonance between otherwise disparate images—a layering of meanings, forming connections previously not perceived. Kindred forms of resonance may exist, between individual verses, in their patterns of rhyme or rhythm.

Poetry has a long and varied history, evolving differentially across the globe. It dates back at least to prehistoric times with hunting poetry in Africa and to panegyric and elegiac court poetry of the empires of the Nile, Niger, and Volta River valleys. Some of the earliest written poetry in Africa occurs among the Pyramid Texts written during the 25th century BCE. The earliest surviving Western Asian epic poem, the Epic of Gilgamesh, was written in the Sumerian language. Early poems in the Eurasian continent include folk songs such as the Chinese Shijing, religious hymns (such as the Sanskrit Rigveda, the Zoroastrian Gathas, the Hurrian songs, and the Hebrew Psalms); and retellings of oral epics (such as the Egyptian Story of Sinuhe, Indian epic poetry, and the Homeric epics, the Iliad and the Odyssey). Ancient Greek attempts to define poetry, such as Aristotle's Poetics, focused on the uses of speech in rhetoric, drama, song, and comedy. Later attempts concentrated on features such as repetition, verse form, and rhyme, and emphasized aesthetics which distinguish poetry from the format of more objectively-informative, academic, or typical writing, which is known as prose. Poets – as, from the Greek, "makers" of language – have contributed to the evolution of the linguistic, expressive, and utilitarian qualities of their languages. In an increasingly globalized world, poets often adapt forms, styles, and techniques from diverse cultures and languages. A Western cultural tradition (extending at least from Homer to Rilke) associates the production of poetry with inspiration – often by a Muse (either classical or contemporary), or through other (often canonised) poets' work which sets some kind of example or challenge.

Some scholars believe that the art of poetry may predate literacy, and developed from folk epics and other oral genres. Others, however, suggest that poetry did not necessarily predate writing.

The oldest surviving epic poem, the Epic of Gilgamesh, dates from the 3rd millennium BCE in Sumer (in Mesopotamia, present-day Iraq), and was written in cuneiform script on clay tablets and, later, on papyrus. The Istanbul tablet #2461, dating to c. 2000 BCE, describes an annual rite in which the king symbolically married and mated with the goddess Inanna to ensure fertility and prosperity; some have labelled it the world's oldest love poem. An example of Egyptian epic poetry is The Story of Sinuhe (c. 1800 BCE).

Other ancient epics includes the Greek Iliad and the Odyssey; the Persian Avestan books (the Yasna); the Roman national epic, Virgil's Aeneid (written between 29 and 19 BCE); and the Indian epics, the Ramayana and the Mahabharata. Epic poetry appears to have been composed in poetic form as an aid to memorization and oral transmission in ancient societies.

Other forms of poetry, including such ancient collections of religious hymns as the Indian Sanskrit-language Rigveda, the Avestan Gathas, the Hurrian songs, and the Hebrew Psalms, possibly developed directly from folk songs. The earliest entries in the oldest extant collection of Chinese poetry, the Classic of Poetry (Shijing), were initially lyrics. The Shijing, with its collection of poems and folk songs, was heavily valued by the philosopher Confucius and is considered to be one of the official Confucian classics. His remarks on the subject have become an invaluable source in ancient music theory.