The wedge-tailed hillstar (Oreotrochilus adela) is a species of hummingbird in the "coquettes", tribe Lesbiini of subfamily Lesbiinae.

The adult male has a glittering green gorget and chestnut underparts with a bold black stripe down the center.

[5] The wedge-tailed hillstar is found from southern La Paz Department in central Bolivia south barely into Jujuy Province in extreme northwestern Argentina.

[5] The wedge-tailed hillstar feeds on nectar from flowering plants; examples include those of genera Barnadesia, Mutisia, and Puya; various mistletoes; and columnar cacti.

Males court by alternately singing and displaying from an open perch and making a deep U-shaped flight.

The male wedge-tailed hillstar's display song is "a medley of intense twittering notes interspersed by a distinct descending cadence".