The red-billed teal was formally described in 1789 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 the "Crimson-billed duck" that had been described in 1785 by the English ornithologist John Latham in his A General Synopsis of Birds.

[6] The red-billed teal is 43–48 centimetres (17–19 in) long and has a blackish cap and nape, contrasting pale face, and bright red bill.

This is a quiet species, but the displaying male has a whzzt call, whereas the female has a soft mallard-like quack.

The red-billed teal is a bird of freshwater habitats in fairly open country and is an omnivore.