The White-necked Hawk (Leucopternis lacernulatus) is a species of bird of prey in the Accipitridae family.

Its natural habitats are subtropical or tropical moist lowland forests, subtropical or tropical moist montanes, and plantations. The species feeds on insects and other invertebrates. It is an opportunistic feeder that will feed on prey flushed by army ants, monkeys or even humans. It is endemic to Brazil and threatened by habitat loss.