Tropic Bird, a family of graceful oceanic birds found on tropical and subtropical seas around the world. There are only three species in the family—the red-billed tropic bird; the red-tailed tropic bird; and the white-tailed, or yellow-billed, tropic bird. These birds range from 16 to 20 inches (40 to 50 cm) in length, not including two elongated tail feathers each about one foot (30 cm) long.

All species are white with a few black markings on the head and wings. Occasionally some individuals have a pink or orange sheen on their bodies. Tropic birds feed on small fish and squid. Tropic birds, which make no nests, lay one white or brown egg on the open ground, often on cliffs.

Tropic birds make up the family Phaethontidae. The red-billed tropic bird is Phaethon aethereus; the red-tailed, P. rubricauda; the white-tailed, P. lepturus.