The natural range of the genus is restricted to the Pacific Ocean, except for Hemigrapsus affinis which lives along the Atlantic coasts of South America, from Cape São Roque (Rio Grande do Norte state, Brazil) to the San Matías Gulf, (Patagonia, Argentina).
The native range of Hemigrapsus penicillatus extends from the Russian Far East (Kuril Islands and Aniva Bay) along the coasts of Japan, China, Taiwan and Korea, as far south-west as Hong Kong.