The crimson-collared tanager is a rather small Middle American songbird. It was first described by the French naturalist René-Primevère Lesson in 1831, its specific epithet from the Latin adjective “sanguinolentus”, “bloodied”, referring to its red plumage.

The crimson-collared tanager (Ramphocelus sanguinolentus) is a rather small Middle American songbird.

Crimson-collared tanagers average 19–20 cm (7.5–8 in) long. The adult plumage is black with a red collar covering the nape, neck, and breast (remarkably similar to the pattern of the male crimson-collared grosbeak).

All tail coverts are also red. The bill is striking pale blue and the legs are blue-gray. In adults, the irides are crimson, contrary to what is shown in Howell and Webb. Females average slightly duller than males, but are sometimes indistinguishable from them. Juvenile birds are similar except that the hood is dull red, the black areas are tinged with brown, and the breast is mottled red and black.

The crimson-collared tanager ranges from southern Veracruz and northern Oaxaca in Mexico through the Atlantic slope of Central America, to the highlands of western Panama.