The eastern spot-billed duck was described by the English biologist Robert Swinhoe in 1866 under its current binomial name Anas zonorhyncha.

[6] Base on this observation, the American Ornithologists' Union recognised the eastern spot-billed duck as a separate species in 2008.

[12][13] These are mainly grey ducks with a paler head and neck and a black bill tipped bright yellow.

[14] The eastern spot-billed duck is migratory, wintering in southern China and possibly Southeast Asia.

The populations in Japan and the Russian Far East have expanded their range northwards by more than 500 km since the early 20th century, possibly in reaction to global warming.

[11] It is a bird of freshwater lakes and marshes in fairly open country and feeds by dabbling for plant food mainly in the evening or at night.