The greater crested tern (Thalasseus bergii) is a seabird in the family Laridae. It is a large tern, 4656 cm (1822 in) in length, with a wingspan of 127145 cm (5057 in). It has a black crown and nape, a white forehead and face, and a long, pointed black bill. The upperparts are pale grey and the underparts are white. The legs and feet are black.
The greater crested tern is found in tropical and subtropical waters around the world. It is a migratory species, breeding in the northern hemisphere and wintering in the southern hemisphere. The greater crested tern feeds on fish, which it catches by diving from the air. It is also known to eat other birds, insects, and squid.