Coscinasterias muricata is a species of starfish in the family Asteriidae. It is a large 11-armed starfish and occurs in shallow waters in the temperate western Indo-Pacific region.

Description C. muricata is the largest starfish in southern Australia and can reach a diameter of 50 cm (20 in). It has seven to fourteen arms, with eleven being the commonest number. The aboral (upper) surface of the arms has longitudinal rows of short spines along the surface and margins and the oral (lower) surface has two rows of tube feet. The colour is orange mottled with shades of blue, green, grey and reddish-brown. This starfish is prone to shedding its arms, making it asymmetric until new arms have grown.

Distribution and habitat C. muricata is native to temperate parts of the western Indo-Pacific region. Its range extends in Australia from Houtman Abrolhos in Western Australia to southern Australia, Tasmania and eastern Australia as far north as Port Denison in Queensland. It is also found in New Zealand, Lord Howe Island and Norfolk Island.