Coordinates: 35°34′00″N 139°44′00″E / 35.566667°N 139.733333°E
Ōmori (大森?) is a district located a few kilometres south of Shinagawa, Tokyo, Japan accessed by rail via the Keihin Tohoku line, or by road via Dai Ichi Keihin. Ōmorikaigan, the eastern area of Ōmori, can be reached via the Keikyu line.
Ōmori is one of many areas in Tokyo's largest ward, Ota-ku, and was formerly home to the German International School before its relocation to Yokohama. High quality residential and retail developments that the German school attracted are present in the Ōmori-sannō area. Ōmori is home to the headquarters of the automotive company Isuzu, which has offices in the Belport complex a few hundred metres from Ōmori station.
Prior to its development as a convenient residential and business location, Ōmori was laced with a network of small rivers which were used by many locals for drying harvested nori (seaweed), a staple of the Japanese diet. Modern Ōmori is built on mostly reclaimed land, and is very much a traditional Shinto area; there are many shrines in the area, and during the August o-bon festival, mikoshi parades are very common.