Tokyo 18th District (東京都第18区, Tōkyō-tō dai-jūhachi-ku, or 東京18区 Tōkyō jūhachi-ku) is a constituency of the House of Representatives in the Diet of Japan.

Before the electoral reform of 1994, the area had been part of Tokyo 7th district, where four representatives were elected by Single non-transferable vote (SNTV).

From its creation to 2012, the district was represented by former Prime Minister and popular Democratic Party co-founder Naoto Kan.

In the election of 2005 it was the only constituency the opposition could defend in Tokyo against the landslide for Junichiro Koizumi's ruling coalition.

[2] Tsuchiya who failed to unseat Kan in 2005 was a representative for the Tokyo proportional representation block where he ranked second on the LDP's list 2005.