The Hispaniolan trogon, also known as cacos is a species of bird in the family Trogonidae. It is endemic to Hispaniola in the Caribbean. It is one of the only two trogon species found in the Caribbean. It is the national bird of Haiti.

The trogons and quetzals are birds in the order Trogoniformes which contains only one family, the Trogonidae. The family Trogonidae contains 46 species in seven genera. The fossil record of the trogons dates back 49 million years to the Early Eocene. They might constitute a member of the basal radiation of the order Coraciiformes and order Passeriformes or be closely related to mousebirds and owls. The word trogon is Greek for "nibbling" and refers to the fact that these birds gnaw holes in trees to make their nests.