The blue-winged warbler (Vermivora cyanoptera) is a fairly common New World warbler, 11.5 cm (4.5 in) long. It breeds in eastern North America in southern Ontario and the eastern United States. Its range is extending northwards, where it is replacing the very closely related golden-winged warbler, Vermivora chrysoptera.
The common name blue-winged warbler refers to the bluish-gray color of the wings that contrast with the bright yellow body of the male. The name of the genus Vermivora means "worm-eating". The genus used to include nine other new world warblers but now includes only the golden-winged warbler and Bachman's warbler which is believed to be extinct.
The blue-winged warbler was one of the many species originally described by Carl Linnaeus in his 18th-century work, Systema Naturae, though the scientific name has changed several times. The species epithet Pinus was given by Linnaeus in 1766 but was a mistake as the original description of the species was actually based on illustrations of "pine creepers" drawn by others. The drawings depicted two different species, what we now call a pine warbler and blue-winged warbler. In 2010 the blue-winged warbler's scientific name was changed by the American Ornithologists' Union to correct the error. Pine warblers retained the species name Pinus but the species epithet for blue-winged warbler was changed to cyanoptera.