Salmon is a popular food, and its fattier species are very healthy due to its high protein and Omega-3 acids. This type of fat, found mainly in seafood, also seems to lessen symptoms of rheumatoid arthritis. Omega-3s lower blood pressure in some patients suffering from hypertension. Also, Omega-3s seem to have a protective effect against some forms of cancer. Salmon is a good source of B vitamins.

According to reports, farmed salmon may contain high levels of dioxins. Polychlorinated biphenyl levels may also be up to 8 times higher in farmed salmon compared to wild salmon, and Omega-3 content may also be lower than wild caught species. Wild salmon are a healthy food, but the benefits of eating even farmed salmon still outweigh the risks. Salmon is generally a red-flesh fish, although there are some examples of white fleshed wild salmon. A rule of thumb is that the vast majority of Atlantic salmon available on the world market is farmed (greater than 99%), whereas the majority of Pacific salmon is wild-caught (greater than 80%).

Several types of salmon are sold commercially. Chinook, or king salmon, the largest and fattiest fish, has firm, usually deep red flesh. Chinook is sold fresh, frozen, and smoked. Sockeye (also called red or blueback), the finest canned salmon has deep-red meat and the next-highest fat content. Coho, or silver salmon, is a small fish with medium-red, less fatty flesh; usually it is sold fresh. Chum, or dog salmon, is a lower-fat fish with firm, sometimes coarse, pale flesh. Pink, or humpback, is the leanest salmon. It has soft, bland, pink flesh that is usually canned.

Salmon live in the Atlantic and Pacific Oceans, as well as the Great Lakes and other land locked lakes. The Kamchatka Peninsula, in the Russian Far East, contains the world's greatest salmon sanctuary. Salmon are anadromous: they are born in fresh water, migrate to the ocean, then return to fresh water to reproduce. The wild salmon find mates in their native streams then the female salmon lays salmon eggs in the bottom gravel nests. After living and growing in the open ocean, the adult salmon will return to its native stream, breed, spawn and die. Salmon population levels are of concern in the Atlantic and some parts of the Pacific but in northern BC and Alaska stocks are still abundant.

Both Atlantic and Pacific Salmon are important to recreational fishing around the world. Freshwater streams and estuaries provide important habitat for many salmon species. They feed on terrestrial and aquatic insects, amphipods, and other crustaceans while young, and primarily on other fish when older. Many wild salmon stocks have seen a marked decline in recent decades, especially the north Atlantic populations which spawn in western European waters. The cause of this decline is not well understood but is likely to include a number of factors.

Canned salmon in the U.S. is usually wild Pacific catch, though some farmed salmon is available in canned form. Alaskan salmon is always wild catch. Smoked salmon is another popular preparation method, and can either be hot or cold smoked. Eating raw salmon in sushi bars or rare salmon in restaurants is generally safe because the fish is frozen (which kills harmful parasites) before serving.