Seals have a wide range of habitats in the Northern and Southern Hemispheres, depending on their species. The one thing all seal habitats have in common is the fact that they all include water.

Seals are semi-aquatic mammals and are classified as Pinnipeds. They spend most of their lives in the water, coming onshore to breed, give birth and escape from predators. Some species, such as the Harp seal, prefer the cold waters and climate of the Arctic, while others, such as the Harbor seal, prefer the waters of the Pacific and range from Alaska to Baja, Mexico. Leopard seals are most common in the waters of the Antarctic but also live in smaller numbers on the shores of Australia, New Zealand, the Cook Islands and even off the coast of South America.

All seals share some general physical characteristics. They all have streamlined bodies for moving through the water and four flippers. Their bodies are covered in soft fur, and under their skin all seals have a layer of blubber which helps insulate them from cold temperatures. However, seals that live in colder climates have more blubber than those that live in warmer climates, even within the same species of seal.