The blue duck (Hymenolaimus malacorhynchos) is a species of duck, endemic to New Zealand.

Blue Duck may also refer to:

Blue Duck (outlaw) (1858?–1895), an outlaw of the American Old West Blue Duck (Lonesome Dove series), a fictional character Blue Duck River, a river in New Zealand Blue Duck (missile), anti-submarine warfare missile, entered service as the Ikara The Blue Duck Inn, a historic hotel in Australia

See also Swedish Blue, a breed of domesticated duck Blue-billed duck (Oxyura australis), an Australian stiff-tailed duck