The yellow-billed teal is a South American species of duck. Like other teals, it belongs to the diverse genus Anas; more precisely it is one of the "true" teals of subgenus Nettion. It occurs in Argentina, the Falkland Islands, Chile, Peru, Bolivia, Uruguay, and Brazil. It has also established itself in South Georgia, where it was first recorded breeding in 1971, and has been recorded as far east as Tristan da Cunha. It inhabits freshwater wetlands, preferring palustrine habitat to rivers. Considering its wide range and local abundance, it is not considered threatened by the IUCN.

Anas is a genus of dabbling ducks. It includes the pintails, most teals, and the mallard and its close relatives. It formerly included additional species but following the publication of a molecular phylogenetic study in 2009 the genus was split into four separate genera. The genus now contains 31 living species. The name Anas is the Latin for "duck".