Ōta (大田区, Ōta-ku) is a special ward in the Tokyo Metropolis in Japan. The ward refers to itself in English as Ōta City. It was formed in 1947 as a merger of Ōmori and Kamata following Tokyo City's transformation into Tokyo Metropolis. The southernmost of the 23 special wards, Ōta borders the special wards of Shinagawa, Meguro and Setagaya to the north, and Kōtō to the east. Across the Tama River in Kanagawa Prefecture is the city of Kawasaki, forming the boundaries to the south and west.

Ōta is the largest special ward in Tokyo by area, spanning 59.46 square kilometres (22.96 sq mi). As of 2024, the ward has an estimated population of 744,849, making it the third largest special ward by population, with a population density of 12,041 inhabitants per square kilometre (31,190/sq mi).

Notable neighborhoods and districts of Ōta include Kamata, the administrative center of the ward where the Ward Office and central Post Office is located, and Den-en-chōfu(田園調布), known for its wealthy residents and luxury homes. Haneda Airport, the busiest airport in Japan by passenger traffic is located in the ward.

The ward was founded on March 15, 1947, merging the old wards of Ōmori and Kamata. The ward's name originates from the combination of letters of the two merging wards, Ōmori (大森) and Kamata (蒲田), combined into 大田 (Ōta). The ward was previously second behind Setagaya in terms of being the largest special ward in Tokyo by area, but due to land reclamation in the Tokyo Bay for the expansion of the Haneda Airport(羽田空港), Ōta overtook Setagaya for first place.

Haneda Airport, now one of the two main domestic and international airports serving the Greater Tokyo Area (the other one being Narita Airport in Narita, Chiba) was first established as Haneda Airfield in 1931 in the town of Haneda, Ebara District of Tokyo Prefecture. Following Japan's surrender in 1945, the airfield was turned into the Haneda Army Air Base under the control of the United States Army. In the same year, Allied occupational authorities ordered the expansion of the airport, evicting people from the surroundings on 48 hours' notice. With the end of the occupation, the Americans returned part of the facility to Japanese control in 1952, completing the return in 1958. Haneda Airport first handled international traffic for Tokyo for the 1964 Tokyo Summer Olympics. Following the opening of Narita Airport in 1978, almost all international flights (with the exception of Taiwanese airlines) moved its operations to Narita Airport. International flights resumed in 2010 following the construction of a new International terminal.

Former Ōmori Ward

Former Kamata Ward

Ōta is run by a city assembly of 50 elected members. The current mayor is Akimasa Suzuki since 2023, an independent affiliated with the Liberal Democratic Party.

Ōta is represented in the Tokyo Metropolitan Assembly by the Ōta district with seven representatives, while it is represented in the House of Representatives by the Tokyo 3rd and Tokyo 4th single-member districts.

As of April 2024, the current composition of the assembly is:

Governing parties: (30 seats)

• Liberal Democratic Party (15 seats)
• Komeito (11 seats)
• Tomin First no Kai (2 seats)
• Democratic Party for the People (1 seat)
• Independent (1 seat)

Opposition parties: (11 seats)

• Japanese Communist Party (5 seats)
• Constitutional Democratic Party (4 seats)
• Reiwa Shinsengumi (1 seat)
• Fair Democracy (1 seat)

Non-aligned parties (9 seats)

• Ishin no Kai (5 seats)
• Sanseito (1 seat)
• Rise up Japan (1 seat)
• Independent (2 seats)

• 2007 Ōta local election

• Ikegami Honmon-ji, a Buddhist temple of the Nichiren Shū.
• Ōmori Shell Mound site
• Senzoku Pond, where Nichiren is said to have washed his feet. The grave of Katsu Kaishū is nearby.
• Tamagawadai Park
• Tokyo Wild Bird Park
• Omori Nori Museum

• Haneda Airport

• JR East
  • Keihin-Tōhoku Line: Ōmori, Kamata Stations

• Keikyū Corporation
  • Main Line: Heiwajima, Ōmorimachi, Umeyashiki, Keikyū-Kamata, Zōshiki, Rokugōdote Stations
  • Airport Line: Keikyū-Kamata, Kojiya, Ōtorii, Anamori-inari, Tenkūbashi, Haneda Airport Terminal 3, Haneda Airport Terminal 1·2 Stations
• Tokyu Corporation
  • Tamagawa Line: Tamagawa, Numabe, Unoki, Shimomaruko, Musashi-nitta, Yaguchinowatashi, Kamata Stations
  • Ikegami Line: Nagahara, Senzoku-ike, Ishikawa-dai, Yukigaya-ōtsuka, Ontakesan, Kugahara, Chidorichō, Ikegami, Hasunuma, Kamata Stations
  • Ōimachi Line: Kita-Senzoku, Ookayama Stations
  • Tōyoko Line: Den-en-chōfu, Tamagawa Stations
  • Meguro Line: Ookayama, Den-en-chōfu, Tamagawa Stations
• Toei Subway
  • Asakusa Line: Magome, Nishi-magome Stations
• Tokyo Monorail
  • Haneda Airport Line: Ryutsu Center, Shōwajima, Seibijō, Tenkūbashi, Haneda Airport Terminal 3, Shin Seibijō, Haneda Airport Terminal 1, Haneda Airport Terminal 2 Stations

• Shuto Expressway
  • No. 1 Haneda Route (Edobashi JCT - Iriya)
  • B Bayshore Route (Namiki - Kawasaki-ukishima JCT)
• National highways
  • Route 1
  • Route 15
  • Route 133
  • Route 357

The following companies have their headquarters in Ōta.

• ANA Wings (subsidiary of All Nippon Airways)
• Alps Electric
• Canon
• Disco Corporation, manufacturer of semiconductor production equipment
• Ebara
• Ikegami Tsushinki, manufacturer of broadcast equipment
• Skymark Airlines
• Takasago International Corporation, a flavours and fragrances company
• Toyoko Inn

Namco, best known for video game franchises such as Pac-Man, Galaxian, and Ace Combat, were headquartered in Ota. The company moved its operations there in 1985, using the funds generated from the successful Family Computer port of Xevious to fund the construction of its office. The building was taken over by Namco Bandai Games after it absorbed Namco in 2006, and later by an unrelated Namco company that focused on video arcades and theme parks. The newer Namco company moved out of the building in 2014 and it was demolished two years later.

Prior to the merger with Japan Airlines, Japan Air System had its headquarters at Haneda Airport in Ōta.

In 2000 All Nippon Airways was headquartered by Tokyo International Airport in Ōta. In 2002 Air Nippon was headquartered on the fifth floor of the Utility Center Building (ユーティリティセンタービル, Yūtiriti Sentā Biru) at Haneda Airport in Ōta. The ANA subsidiary Air Nippon Network was also based at the airport.

Before its dissolution, Galaxy Airlines was headquartered in the ARC Building on the airport grounds.

Sega and its parent company Sega Sammy Holdings, best known for its Sonic the Hedgehog franchise, was originally headquartered in Ōta. However, Sega Sammy Holdings announced in April 2017 that it would relocate its head office functions and domestic subsidiaries to Shinagawa-ku by January 2018. This was to consolidate scattered head office functions including Sega Sammy Holdings, Sammy Corporation, Sega Holdings, Sega Games, Atlus, Sammy Network, and Dartslive. After the relocation to Shinagawa was complete, Sega's previous headquarters in Ōta was later sold in February 2019 and will likely be torn down.

Gakken was headquartered in Ōta from 1962 until 2008 when they moved their headquarters to Shinagawa.

• Toho University Ōmori Campus
• Tokyo Institute of Technology Ōokayama Campus
• Showa University Senzoku Campus
• Tokyo University of Technology Kamata Campus

The following public high schools are located in Ōta, operated by the Tokyo Metropolitan Government Board of Education.

• Den Enchofu High School (東京都立田園調布高等学校)
• Kamata High School (東京都立蒲田高等学校)
• Mihara High School (東京都立美原高等学校)
• Omori High School (東京都立大森高等学校)
• Ota Sakuradai High School (東京都立大田桜台高等学校)
• Rokugoh Technical High School (東京都立六郷工科高等学校)
• Tsubasa Sogo High School (東京都立つばさ総合高等学校)
• Yukigaya High School (東京都立雪谷高等学校)

• Tokyo High School (東京高等学校)
• Tokyo Jitsugyo High School (東京実業高等学校)

This section needs expansion. You can help by adding to it. (November 2022)

Public elementary and junior high schools are operated by Ōta City Board of Education [ja] (大田区教育委員会).

• Tokyo Korean 6th Elementary School (東京朝鮮第六初級学校) - North Korean school

The Deutsche Schule Tokyo was previously located in Ōta before relocating to Yokohama, Kanagawa Prefecture in 1970.

Ōta operates several public libraries, including:

• Chaoyang, Beijing
• Salem, Massachusetts

• Ōta City Official Website (in Japanese)
• Ōta City Tourism Website (in English)