The black-backed thornbill (Ramphomicron dorsale) is an Endangered species of hummingbird in the "coquettes", tribe Lesbiini of subfamily Lesbiinae.

The male's upperparts are velvety black with purplish uppertail coverts and a white spot behind the eye.

Females have shining grass green upperparts, and like the male, purplish uppertail coverts and a white spot behind the eye.

The tail is shorter than the male's and the outer pair of feathers have white tips.

[5] The black-backed thornbill is restricted to the isolated Sierra Nevada de Santa Marta in far northern Colombia, where it inhabits the edges of humid and elfin forest and also páramo.