[2][3][4] The first formal description of the American pygmy kingfisher was by the German zoologist Peter Simon Pallas in 1764 under the binomial name Alcedo aenea.

The bill is black with some pale yellow at the base of the mandible and its legs and feet are pinkish to light gray.

Males of the nominate subspecies have a dark glossy green head and upperparts with a golden wash separated by a narrow rufous collar.

It is found from the southern Mexican states of Puebla, Veracruz, Yucatán, and Chiapas south through Belize, Guatemala, El Salvador, Honduras, and Nicaragua to central Costa Rica.

From there it occurs west of the Andes to central Ecuador and east and south into Venezuela, the Guianas, and most of Amazonian Colombia, Brazil, Peru, and Bolivia.

[10] The American pygmy kingfisher inhabits dense forest, where it occurs along small streams and rivers, beside pools, in swamps, and along tidal channels in mangroves.

Its diet includes small fish such as those of families Characidae and Cyprinodontidae, tadpoles and frogs, and large insects such as damselflies.

[10][11] The American pygmy kingfisher's breeding season varies geographically, apparently from January in Mexico to as late as September in Trinidad.

Both members of a pair excavate a burrow in a river bank, road cutting, gravel pit, arboreal termitarium, or the root ball of a fallen tree.