The Australian Swiftlet can be found around tropical coastal areas and offshore islands occurring 1,000 metres above sea level but more commonly below 500 metres. It tends to forage in flocks over the edge of the Rainforests, beaches and gorges and sometimes pastures and savannas.

It is an insectivore and a flight feeder who preys on insects and floating spiders. It typically feeds during the day and within 30 kilometres of the breeding colony, returning to the caves at night to roost.

The Australian Swiflet has a high pitched call when in flight. During breeding season, it can be heard uttering a metallic clicking call.

Australian Swiflets have the ability to use a simple but effective form of echolocation to navigate in total darkness through the chasms and shafts of the caves where they roost at night and breed during the breeding season.

These birds also emit a series of low clicks followed by a call when approaching the nests, probably to warn nearby birds out of their way.