A marine mammal park is a commercial theme park or aquarium where marine mammals such as dolphins, beluga whales and sea lions are kept within water tanks and displayed to the public in special shows. A marine mammal park is more elaborate than a dolphinarium, because it also features other marine mammals and offers additional entertainment attractions. It is thus seen as a combination of a public aquarium and an amusement park. Marine mammal parks are different from marine parks, which include natural reserves and marine wildlife sanctuaries such as coral reefs, particularly in Australia.

An oceanarium can be either a marine mammal park, such as Marineland of Canada, or a large-scale aquarium, such as the Lisbon Oceanarium, presenting an ocean habitat with marine animals, especially large ocean dwellers such as sharks.