The blue dacnis or turquoise honeycreeper (Dacnis cayana) is a small passerine bird. This member of the tanager family is found from Nicaragua to Panama, on Trinidad, and in South America south to Bolivia and northern Argentina. It is widespread and often common, especially in parts of its South American range.
The blue dacnis is 12.7 cm long and weighs 13 g. Despite its alternative name, it is not a honeycreeper, which are longer-billed. The adult male is turquoise blue with a black around the eyes, and on the throat and back. The wings and tail are black, edged with turquoise. The female and immature are mainly green with a blue head, paler green underparts and green-edged brown wings. The blue dacnis's call is a thin tsip.