Izu Ōshima
is an inhabited volcanic island in the Izu archipelago in the Philippine Sea, off the coast of Honshu, Japan, east of the Izu Peninsula and southwest of Bōsō Peninsula. As with the other islands in the Izu Island group, Izu Ōshima forms part of the Fuji-Hakone-Izu National Park. Izu Ōshima, at 91.06 km² is the largest and closest of Tokyo's outlying islands, which also include the Ogasawara Islands.