Shearwater, the common name of a family of birds; also the common name of a genus of the family. Members of this genus are sometimes referred to collectively as the “true shearwaters.” The family, with a total of more than 50 species, includes the fulmars and certain species of petrels as well as the true shearwaters.

Birds of this family are drab colored, with sooty gray, brown, or black upper parts and generally white underparts. They have short legs, webbed feet, and large hooked beaks with tubular nostrils. Shearwaters are usually about 15 to 25 inches (38–64 cm) in length, with long pointed wings that span 2 to 2 1/2 feet (60–75 cm) from tip to tip.

Shearwaters are found on all the unfrozen oceans of the world. When a steady wind blows, they will glide with it for more than one mile (1.6 km), just skimming the surface of the water. They feed chiefly on small marine animals. Some feed while floating on the water's surface; others perform shallow dives in search of food. Shearwaters come to land only to nest, returning to the shores or offshore islands where they were reared. One chalky white egg is laid in the nest, built in a burrow in the ground or in a rock crevice.

In some countries, such as Australia and New Zealand, several species of the true shearwaters are called muttonbirds because they are used for food. The sooty shearwater of the Atlantic and Pacific oceans is a muttonbird. It annually breeds on land in the Southern Hemisphere and each spring and summer migrates to the subarctic waters of the Northern Hemisphere.

The shearwater family is Procellariidae; the shearwater genus is Puffinus. The sooty water is P. griseus.