Gadus macrocephalus is a marine fish species in the family Gadidae, commonly known as Pacific cod or Alaska cod. It is native to the North Pacific Ocean, ranging from the Yellow Sea and Sea of Japan northward to the Bering Sea and along the western coast of North America as far south as California. The genus name Gadus is derived from Latin, historically used to denote codfish, while the species epithet macrocephalus comes from Greek makros meaning “large” and kephalē meaning “head,” referring to its relatively large head compared to body size.

Pacific cod has been an important subsistence and commercial species for Indigenous peoples of Alaska and the Russian Far East, as well as for Japanese and Korean coastal communities. In modern fisheries, it is one of the most economically significant groundfish species in the North Pacific, harvested for fresh, frozen, dried, and processed seafood markets. Gadus macrocephalus yields white, lean flesh that is mild in flavor and flaky in texture. It is used in fillets, salted and dried cod products, fish cakes, surimi, roe products, and fish stews. In Japan, it is used in dishes such as nabe (hot pot), grilled preparations, and roe-based specialties, while in Alaska and Russia it has been traditionally air-dried, salted, or fermented for preservation. Cod liver oil may also be extracted from this species, and roe (tarako-type products, though more commonly associated with pollock) is occasionally consumed regionally. It is strongly associated with North Pacific, Alaskan, Japanese, Korean, and Russian Far Eastern cuisines.

Gadus macrocephalus contains eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), vitamin D (cholecalciferol), particularly in the liver, and contains vitamin B12 (cobalamin). Selenium is present as selenomethionine, contributing antioxidant activity. The fish also contains taurine and free amino acids such as glycine and glutamic acid that contribute to flavor. Cod liver oil derived from this species contains high concentrations of fat-soluble vitamins A (retinol) and D, which are heat-stable under moderate cooking but can degrade under prolonged high heat.