Prometheus Unbound is a four-act lyrical drama by Percy Bysshe Shelley, first published in 1820. It is concerned with the torments of the Greek mythological figure Prometheus, who defies the gods and gives fire to humanity, for which he is subjected to eternal punishment and suffering at the hands of Zeus. It is inspired by the classical Prometheia, a trilogy of plays attributed to Aeschylus. Shelley's play concerns Prometheus' release from captivity, but unlike Aeschylus' version, there is no reconciliation between Prometheus and Jupiter (Zeus). Instead, Jupiter is abandoned by his supportive elements and falls from power, which allows Prometheus to be released.

Percy Bysshe Shelley was a British writer who is considered as one of the major English Romantic poets. A radical in his poetry as well as in his political and social views, Shelley did not achieve fame during his lifetime, but recognition of his achievements in poetry grew steadily following his death, and he became an important influence on subsequent generations of poets, including Robert Browning, Algernon Charles Swinburne, Thomas Hardy, and W. B. Yeats. American literary critic Harold Bloom describes him as "a superb craftsman, a lyric poet without rival, and surely one of the most advanced sceptical intellects ever to write a poem."