A Rainbow Boa, or Slender Boa, is one of several terrestrial boas, of genus Epicrates, known for their attractive patterns.

Rainbow Boas are distributed throughout most of Central America, the Caribbean, and South America. The term Rainbow Boa is applied both to the entire genus Epicrates, or to the species Epicrates cenchria (also known as the Slender Rainbow Boa). Some of the other species of Epicrates are also referred to simply as Rainbow Boas, at least locally, because most species and subspecies are confined to particular regions, often islands, and it is rare to find two species in the same locality.

E. cenchria is the species most often kept as a pet, and it has many subspecies, easily distinguishable by their markings, most of which have well established common names. If the term "Rainbow Boa" is used outside the regions to which these snakes are native, it is most likely to refer to this species.