Os Lusíadas (Portuguese pronunciation: [uʒ luˈzi.ɐðɐʃ]), usually translated as The Lusiads, is a Portuguese epic poem written by Luís Vaz de Camões (c. 1524/5 – 1580) and first published in 1572. It is widely regarded as the most important work of Portuguese literature and is frequently compared to Virgil's Aeneid (1st c. BC). The work celebrates the discovery of a sea route to India by the Portuguese explorer Vasco da Gama (1469–1524). The ten cantos of the poem are in ottava rima and total 1,102 stanzas.

Written in Homeric fashion, the poem focuses mainly on a fantastical interpretation of the Portuguese voyages of discovery during the 15th and 16th centuries. Os Lusíadas is often regarded as Portugal's national epic,much as Virgil's Aeneid was for the Ancient Romans, or Homer's Iliad and Odyssey for the Ancient Greeks. It was written when Camões was an exile in Macau and was first printed in 1572, three years after the author returned from the Indies.