Oxyurinae is a sub-family of the duck, goose and swan family of birds, Anatidae.

Most of its members are stiff-tailed ducks, which have, as their name implies, long stiff tail feathers, which are erected when the bird is at rest. Most have relatively large swollen bills. The exception is Black-headed Duck which looks more like a typical duck with a short tail and normal bill.

These are all freshwater diving ducks. Their legs are set far back, making them awkward on land, so they rarely leave the water.

Their unusual displays involve drumming noises from inflatable throat-sacs, head throwing, and erecting short crests. Most display singly, but Musk Ducks "lek" in groups.

Oxyurinae contains the following genera

• Oxyura, 6 species of typical stiff-tailed ducks
  • Ruddy Duck Oxyura jamaicensis
  • Masked Duck Oxyura dominica
  • White-headed Duck Oxyura leucocephala
  • Maccoa Duck Oxyura maccoa
  • Argentine Blue-bill Oxyura vittata
  • Blue-billed Duck Oxyura australis
• Biziura, the Australian Musk Duck.
• Heteronetta, the South American Black-headed Duck
• Stictonetta, the Freckled Duck of southern Australia.