The wood duck or Carolina duck (Aix sponsa) is a partially migratory species of perching duck found in North America. The male is one of the most colorful North American waterfowls.

The wood duck was formally described in 1758 by the Swedish naturalist Carl Linnaeus in the tenth edition of his Systema Naturae under the binomial name Anas sponsa.^[4] Linnaeus based his account on the “summer duck” from Carolina that had been described and illustrated by the English naturalist Mark Catesby in the first volume of his The Natural History of Carolina, Florida and the Bahama Islands that was published between 1729 and 1731.^[5] Linnaeus specified the type locality as North America but this has been restricted to Carolina following Catesby.^[6] The wood duck is now placed together with the mandarin duck in the genus Aix that was introduced in 1828 by the German naturalist Friedrich Boie. The species is monotypic: no subspecies are recognised.^[7] The genus name is an Ancient Greek word for an unidentified diving bird mentioned by Aristotle. The specific epithet sponsa is Latin meaning “bride” (from spodere meaning “pledge”).^[