The mangrove cuckoo was formally described in 1788 by the German naturalist Johann Friedrich Gmelin in his revised and expanded edition of Carl Linnaeus's Systema Naturae.

[2] Gmelin based his description on "Le petit vieillard" or "Coucou des palétuviers" from Cayenne that had been described and illustrated in 1779 by the French polymath Georges-Louis Leclerc, Comte de Buffon.

[3][4] The mangrove cuckoo is now placed with 12 other species in the genus Coccyzus that was introduced in 1816 by the French ornithologist Louis Pierre Vieillot.

[6] Adults have a long tail, brown above and black-and-white below, and a black curved bill with yellow on the lower mandible.

Although the scientific name is minor (meaning "small"), this species is on average the largest of North America's three Coccyzus cuckoos.