A galley is a type of ship propelled by rowers that originated in the Mediterranean region and was used for warfare, trade and piracy from the first millennium BC. Galleys dominated naval warfare in the Mediterranean Sea from the 8th century BC until development of advanced sailing warships in the 16th century. Galleys fought in the wars of Assyria, ancient Phoenicia, Greece, Carthage and Rome until the 4th century AD. After the fall of the Western Roman Empire galleys formed the mainstay of the Byzantine navy and other navies of successors of the Roman Empire, as well as new Muslim navies. Medieval Mediterranean states, notably the Italian maritime republics, including Venice, Pisa, and Genoa, used galleys until the ocean-going man-of-war made them obsolete. The Battle of Lepanto was one of the largest naval battles in which galleys played the principal part.

Galleys were common until the introduction of broadside sailing ships of war into the Mediterranean in the 17th Century, but continued to be applied in minor roles until steam propulsion.