The harbor seal (Phoca vitulina), also known as the common seal, is a true seal found along temperate and Arctic marine coastlines of the Northern Hemisphere. The most widely distributed species of pinniped, they are found in coastal waters of the northern Atlantic and Pacific Oceans and the Baltic and North Seas. They are classified as Least Concern on the IUCN Red List of Threatened Species.

Harbor seals are brown, silvery white, tan, or gray, with distinctive V-shaped nostrils. The females live longer than the males (30–35 years versus 20–25 years).

There are 4 confirmed subspecies of harbor seal, these being:

• Ungava seal (which live in eastern Canadian fresh water)
• Pacific common seal (which live in western North America
• Insular seal (Which live in eastern Asia)
• Eastern Atlantic common seal (which inhabit Europe and western Asia)

Along with these is a supposed fifth subspecies, the Western Atlantic common seal. It inhabits eastern North America, though this subspecies's validity is questionable, and not supported by genetic evidence.

See also

• pinniped
• sea_lion
• seal
• elephant_seal
• harbor_seal
• harp_seal
• leopard_seal
• monk_seal
• spotted_seal
• weddell_seal
• walrus