Hashira Island (柱島, Hashira-jima) is an island in southern Hiroshima Bay of the Inland Sea, Yamaguchi Prefecture, Japan. Located 26 kilometres (16 mi) kilometers southeast of Iwakuni, it is part of the Kutsuna Islands within the Bōyo Islands group. The island covers 3.12 square kilometres (1.20 sq mi) and as of 2013 had a population of 184 residents.