The Giant Swiftlet (Hydrochous gigas), also known as the Waterfall Swift, is a species of swift in the Apodidae family.

It has been suggested that the Giant or Waterfall Swiftlet, Hydrochous gigas, which cannot echolocate, may be descended from an echolocating ancestor.

The Giant Swiftlet (Hydrochous gigas), also known as the Waterfall Swift, is a species of swift in the Apodidae family.

DNA sequence data provides strong support for a basal relationship between A. papuensis and other Aerodramus taxa and suggest that this species and the Waterfall Swift Hydrochous gigas, are sister taxa, a relationship that would indicate paraphyly of the genus Aerodramus.