Starfish are also known as asteroids due to being in the class Asteroidea. About 1,900 species of starfish live on the seabed in all the world's oceans, from warm, tropical zones to frigid, polar regions. They are found from the intertidal zone down to abyssal depths, at 6,000 m (20,000 ft) below the surface.

Common places to find starfish are in tide pools, coral reefs, mud, sand, and kelp forests. They have been discovered as deep as 20,000 feet below the surface of the ocean.

The starfish can´t live outside the water, so they are distributed throughout the oceans of the world, either in cold or tropical waters. It is quite uncommon to find them in freshwater. The preferred habitats of these striking creatures are the marine depths; they adhere to the muddy, sandy areas, between algae and rocks.

Starfish are found in temperate and tropical waters, from polar regions to the equator, making them a truly cosmopolitan species. Their choice of habitat is closely tied to their diet, as starfish are primarily carnivorous.

The natural habitat of starfish spans right from the intertidal zone, i.e., the seashore which is exposed to the air during the low tide and goes underwater during the high tide, to the abyssal zone, which has a depth of roughly about 4000 – 6000 meters.