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 (municipal elections except designated major cities), 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.

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.