The Blue Swallow (Hirundo atrocaerulea) is a small passerine bird in the swallow family. Swallows are somewhat similar in habits and appearance to other aerial insectivores, such as the related martins and the unrelated swifts (order Apodiformes).

The Blue Swallow breeds in southern Africa, wintering further north in Uganda and Kenya.

This bird breeds in montane grassland, preferring high rainfall, undulating areas. In winter it prefers open grassland, with bushes and trees. The nest is usually attached to the roof or side of a hole in the ground.

This species is a small swallow at 18-25cm. It has very long outer tail feathers. It appears all-black, but is actually a deep, metallic blue colour. Females and juveniles have a shorter tail.

This species is classified as Vulnerable due to destruction of its habitat at both its breeding and wintering sites. The current population is estimated at 4,000 and decreasing.