The rufous-gaped hillstar formerly known as White-tailed hillstar is a species of hummingbird in the family Trochilidae, and one of two species in the genus Urochroa. It is found in humid montane forest in southern Colombia, Ecuador, and northern Peru. It has two subspecies, the nominate on the west Andean slope, and leucura on the east Andean slope. The two differ strongly, most conspicuously in that the former has a broad orange malar, which the latter lacks. Both have a straight black bill, greenish upperparts, a blue throat, grey belly, and extensive white to the tail. Although sharing the name hillstar with the members of the genus Oreotrochilus, they are quite different and not closely related.