Onchidoris muricata is a species of sea slug, a dorid nudibranch, a shell-less marine gastropod mollusc in the family Onchidorididae.

[2] This species was described from Norway.

It is currently known from the European coasts of the North Atlantic Ocean as far south as the British Isles and the north-west Atlantic as far south as Maine.

[4][5] It is reported from the north-east Pacific Ocean coasts of North America from Friday Harbor, Washington south to Lion Rock, San Luis Obispo County, California.

[6]