Cherax tenuimanus, known as the hairy marron or Margaret River marron, is one of two species of crayfish in Southwestern Australia known as marron. It occupies a narrow range within the southwestern biogeographical region of Margaret River. It is currently listed as critically endangered on the IUCN Red List, because of the threat from the wider ranged smooth marron, Cherax cainii, which was introduced to its habitat.