Metopograpsus messor is a species of grapsid crab that lives in mangroves from East Africa to Fiji.

[4] The distribution of M. messor extends from East Africa, along the coast of the Indian Ocean, including the Red Sea and the Persian Gulf, and at least as far east as Fiji.

Metopograpsus messor lives in mangroves (including Avicennia marina and Sonneratia alba), as well as on rocky shores.

[4] It lives under rotting wood, and is capable of climbing trees.

[4] Metopograpsus messor was first described under the name Cancer messor by Peter Forsskål in 1775, in his Descriptiones Animalium, Avium, Amphibiorum, Piscium, Insectorum, Vermium, based on material he collected at Suez.