The Sooty Tern, Onychoprion fuscatus is a seabird of the tern family. It is a bird, which is mainly found in the tropical oceans and breeds on the islands throughout the equatorial zone.

It is a large tern, which is similar to the Sandwich Tern. The wings and the tails of the bird are long and it has dark grey upper parts while the lower parts are white. The bill and legs are black in colour. The Sooty Tern is darker backed than the Bridled Tern and has a broader white forehead and no pale neck collar. The call of the bird is loud and piercing making a ker- wack -a -a wack or kvaark. The younger Sooty Terns are scaly grey on the upper and the lower parts.

The Sooty Tern breeds in colonies on rocky or coral islands. It builds its nest in a ground scrape or hole and the normal clutch is one to three eggs. It consumes fish found on the surface of the marine environments.