2023 Japanese by-elections


In 2023, by-elections were held in Japan in order to fill vacancies in the House of Representatives and the House of Councillors, the two houses of the National Diet of Japan.

April by-elections

On 23 April 2023, 5 by-elections were held together with the second phase of the unified local elections, including Yamaguchi 4th district, the seat of former Prime Minister Shinzo Abe who was assassinaed on 8 July 2022.
The ruling Liberal Democratic Party and opposition Japan Innovation Party both made 1 pickup, flipping an Independent and a Democratic Party for the People seat respectively.
ConstituencyHouseOutgoing MPPartyMember electedPartyReason
Chiba 5th districtHouse of RepresentativesKentaro SonouraIndependent Arfiya EriLDPResigned on 19 December 2022
Wakayama 1st districtHouse of RepresentativesShuhei KishimotoDPPYumi HayashiJIPResigned on 1 September 2022
Yamaguchi 2nd districtHouse of RepresentativesNobuo KishiLDPNobuchiyo KishiLDPResigned on 3 February 2023
Yamaguchi 4th districtHouse of RepresentativesShinzo AbeLDPShinji YoshidaLDPAssassinated on 8 July 2022
Ōita at-large districtHouse of CouncillorsKiyoshi AdachiIndependentLDPResigned on 10 March 2023

October by-elections

The October by-elections were held on 22 October 2023 after Nagasaki 4th district representative Seigo Kitamura's death and the resignation of Tokushima-Kōchi at-large district representative Kojiro Takano after beating his secretary. Both representatives were members of the Liberal Democratic Party.
The LDP lost 1 upper house seat to Independent Hajime Hirota who was backed by opposition parties Constitutional Democratic, Communist, and Social Democratic.
ConstituencyHouseOutgoing MPPartyMember electedPartyReason
Nagasaki 4th districtHouse of RepresentativesSeigo KitamuraLDPLDPDied on 20 May 2023
Tokushima-Kōchi at-large districtHouse of CouncillorsKōjirō TakanoLDPHajime HirotaIndependentResigned on 22 June 2023