Metrosideros boninensis is a species of flowering plant in the family Myrtaceae. It is endemic to the Bonin Islands archipelago and is found exclusively on Chichijima Island, excepting for two remaining trees located on neighboring Anijima Island. M. boninensis is classified as ‘endangered’ in the Japanese Red Data Book and, although there were 326 plants recorded in 2004, genetic diversity of M. boninensis is extremely low.