Pollock is the common name used for either of the two species of marine fish in the Pollachius genus. Both P. pollachius and P. virens are commonly referred to as pollock. Other names for P. pollachius include the Atlantic pollock, European pollock, lieu jaune, and lythe; while P. virens is sometimes known as Boston blues (distinct from bluefish), coalfish (or coley), Silver Bills or saithe.

Both species can grow to 3 ft 6 in (1.07 m) and can weigh up to 46 lb (21 kg). The fish has a strongly-defined silvery lateral line running down the sides. Above the lateral line the color is a greenish black. The belly is white. It can be found in water up to 100 fathoms (180 m) deep over rocks, and anywhere in the water column. Pollock are a "whitefish". They are an important part of the New England and North Atlantic fisheries, though less so than cod and haddock. They spawn in late winter and early spring on Georges Bank, off the New England coast.