[clarification needed] The chestnut teal was described by the English naturalist Thomas Campbell Eyton in 1838 under the binomial name Mareca castanea.

[3] A large molecular phylogentic study that compared mitochondrial DNA sequences from ducks, geese and swans in the family Anatidae found that the chestnut teal is a sister species to the Sunda teal (Anas gibberifrons) that is endemic to Indonesia.

The female chestnut teal has a loud penetrating "laughing" quack repeated rapidly nine times or more.

Tasmania and southern Victoria are the species' stronghold,[5] while vagrants have been found as far north as New Guinea and Lord Howe Island, and as far south as New Zealand.

Chestnut teals form monogamous pairs that stay together outside the breeding season, defend the nest site and look after the young when hatched.