The tropical forms S. d. korustes and S. d. bangsi are resident breeders from east Africa across the Indian Ocean to Japan. They have more red on the bill. The long-billed and short-winged S. d. gracilis breeds in Australia and New Caledonia.
This species breeds in colonies on coasts and islands. It nests in a ground scrape and lays one to three eggs. Like all white terns, it is fiercely defensive of its nest and young and will attack humans and other large predators, usually attacking the back of the head.
As with other Sterna terns, Roseate Tern feeds by plunge-diving for fish, usually from saline environments. It usually dives directly, and not from the "stepped-hover" favoured by Arctic Tern. The offering of fish by the male to the female is part of the courtship display.
Its thin sharp bill is black with a red base when breeding, which is more extensive in the tropical and southern hemisphere races. It is shorter-winged and has faster wing beats than Common or Arctic Tern.
Roseate Tern's upper wings are pale grey and its under parts white, and this tern looks very pale in flight, like a small Sandwich Tern, although the outermost primary flight feathers darken during the summer. The adults have very long tail streamers and red legs. The call is a characteristic cherrick.
In winter, the forehead becomes white and the bill black. Juvenile Roseate Terns have a scaly appearance like juvenile Sandwich Terns.