Tokyo 1st district (東京都第1区, Tōkyō-to dai-ikku or 東京1区, Tōkyō ikku) is a constituency of the House of Representatives in the Diet of Japan (national legislature). It is located in eastern mainland Tokyo and covers central parts of the former city of Tokyo. The district consists of the wards of Chiyoda (which includes the central government buildings) and Shinjuku. As of 2016, 514,974 eligible voters were registered in the district.[1] Before redistricting in 2022, the district included a part of Minato ward which is now in the 7th district.
The two main candidates contesting the district until 2009, Banri Kaieda (DPJ, Hatoyama group) and Kaoru Yosano (formerly LDP, without faction), had represented the old multi-member 1st district of Tokyo. In 2012, Yosano retired, and LDP newcomer Miki Yamada narrowly beat Kaieda, who was re-elected to a proportional seat leading the Democratic list in Tokyo with a sekihairitsu of 98.6%.[2] Kaieda regained the seat in the 2017 election.[3] The seat has been alternately won by Kaieda and Yamada since then.