The blue bunting (Cyanocompsa parellina) is a species of passerine in the family Cardinalidae, the cardinals or cardinal grosbeaks. It is found in Belize, El Salvador, Guatemala, Honduras, Mexico, and Nicaragua.
The nominate subspecies of blue bunting is 13 to 14 cm long. Males weigh 11 to 24 g and females 9.8 to 21 g. The nominate male is various shades of blue, sky blue on the forehead and cheek, blackish blue on the upperparts, ultramarine on the rump, and the underparts from chin to belly deep blue. The adult and immature females are overall dull browish, with a reddish tinge to the belly. The immature male is overall gray-blue with a browish wash on the belly.
Compared to the nominate, the C. p. beneplacita male is a duller blue and the female paler and with less of a reddish tinge on the belly. The male C. p. lucida's blue is between those of the nominate and C. p. beneplacita and the sky blue covers more of its head. The female is similar to that of beneplacita. The male C. p. indigotica is dull indigo on the darker areas and cerulean on the lighter ones; the female is lighter brown than the nominate.