Endemic to Colombia, where it is found very locally in all three Andean ranges, Turquoise Dacnis is sufficiently rare and threatened by ongoing deforestation to be classified as Vulnerable by BirdLife International. It is a small, short-billed tanager. Males are blue with a black mask, throat, mantle, tail, and wings, while females are dull brown above (grayer on the head), with grayish underparts, becoming yellowish over the central breast and belly. Both sexes have yellow irides. This species inhabits humid lower montane forest and edge, but has been found in shade-tree plantations at one locality.
This species was previously known as the Turquoise Dacnis-Tanager (Pseudodacnis hartlaubi), but is now recognized as being a true Dacnis. In Spanish the common name is Dacnis Turquesa (Hilty 2011, de Juana et al. 2012). Turquoise Dacnis, named for the German ornithologist Karel Johann Gustav Hartlaub, derives its English name from its brilliant turquoise color. The genus name "Dacnis", derived from the Greek "daknis", refers to a bird from Egypt (Jobling 2010).