"On First Looking into Chapman's Homer" is a sonnet written by the English Romantic poet John Keats (1795–1821) in October 1816. It tells of the author's astonishment while he was reading the works of the ancient Greek poet Homer as translated by the Elizabethan playwright George Chapman.

John Keats was an English poet of the second generation of Romantic poets, along with Lord Byron and Percy Bysshe Shelley. His poems had been in publication for less than four years when he died of tuberculosis at the age of 25. They were indifferently received in his lifetime, but his fame grew rapidly after his death. By the end of the century, he was placed in the canon of English literature, strongly influencing many writers of the Pre-Raphaelite Brotherhood; the Encyclopædia Britannica of 1888 called one ode "one of the final masterpieces".