The orange-bellied euphonia (Euphonia xanthogaster) is a species of bird in the finch family, Fringillidae. They were formerly considered tanagers (Thraupidae). It is found in Bolivia, Brazil, Colombia, Ecuador, Guyana, Panama, Peru, and Venezuela. Its natural habitats are subtropical or tropical moist lowland forest and subtropical or tropical moist montane forest.
The black-throated euphonia ("Euphonia vittata") is now thought to be a hybrid between the orange-bellied euphonia and the chestnut-bellied euphonia.
Eleven subspecies are recognised: E. x. oressinoma Olson, 1981 – northwest Colombia E. x. chocoensis Hellmayr, 1911 – east Panama to northwest Ecuador E. x. badissima Olson, 1981 – north Colombia and northwest Venezuela E. x. quitensis (Nelson, 1912) – west Ecuador and northwest Peru E. x. dilutior (Zimmer, JT, 1943) – southeast Colombia and northeast Peru E. x. cyanonota Parkes, 1969 – west, central Brazil E. x. brunneifrons Chapman, 1901 – southeast Peru E. x. ruficeps d'Orbigny & Lafresnaye, 1837 – west Bolivia E. x. brevirostris Bonaparte, 1851 – east Colombia to south Venezuela, Guianas, northwest Brazil and east Peru E. x. exsul Berlepsch, 1912 – northeast Colombia and north Venezuela E. x. xanthogaster Sundevall, 1834 – east Brazil