The greater Caribbean region has played an important role in the early diversification of Croton L. (Euphorbiaceae s.s.). Jamaica is also important to Croton taxonomy because several of the earliest described species were based on material from the island. The Jamaican species of Croton are found in five distinct clades indicating that there were at least five separate over-water dispersal events of the genus to the island. Croton jamaicensis (section Eluteria Griseb.), a new species endemic to limestone hills along the southern coast of Jamaica, is described and illustrated. The species is phylogenetically most closely related to C. laurinas Sw. and C. grisebachianus Müll. Arg., both also endemic to Jamaica. Several lectotypifications and novel synonymies are required to clarify the taxonomy of the species of Croton that have been described from Jamaica, some of which are widespread in the region.