The suborder of the mammalian order Carnivora comprising the aquatic carnivores.

It includes seals, sea lions, and walruses. Species occur in coastal marine habitats, most commonly in temperate or subpolar regions.

The body is fusiform (shaped like a spindle, wider in the middle and tapering toward the ends) and streamlined. Each limb bears five broad, flattened digits.

The ears and nostrils are modified to close under water. Some species are capable of diving to 600 meters.