The Cottidae are a family of fish in the superfamily Cottoidea, the sculpins. It is the largest sculpin family, with about 275 species in 70 genera. They are referred to simply as cottids to avoid confusion with sculpins of other families.
Cottids are distributed worldwide, especially in boreal and colder temperate climates. The center of diversity is the northern Pacific Ocean. Species occupy many types of aquatic habitats, including marine and fresh waters, and deep and shallow zones. A large number occur in near-shore marine habitat types, such as kelp forests and shallow reefs. They can be found in estuaries and in bodies of fresh water.
Most cottids are small fish, under 10 cm (3.9 in) in length. The species Scorpaenichthys marmoratus can be up to 78 cm (31 in) in length. They vary in coloration and patterning between species and between individuals of some species, and sometimes between sexes. Their eyes are large and placed high on the head. Adults lack swim bladders.
The genera of the family include: