The adult of a new genus and new species of Muscidae, Callainireinwardtia woodi sp. nov, gen. nov., is described from Costa Rica. This new genus is placed in the tribe Reinwardtiini and can be distinguished from other members of the group as well as other New World Muscidae by the presence of a striking blue to blue-green metallic color combined with a bare anepimeron, setulose metepisternum, a plumose arista, and wings without clouds or spots. Conflicting data on the phylogenetic position of the reinwardtiine genera is summarized and potential avenues for future research are suggested.