| Tadatomo Yoshida | |
| Office: | Chairman of the Social Democratic Party |
| Term Start: | 14 October 2013 |
| Term End: | 25 February 2018 |
| Predecessor: | Seiji Mataichi (acting) |
| Successor: | Seiji Mataichi |
| Office1: | Member of the House of Councillors |
| Term Start1: | 29 July 2019 |
| Term End1: | 30 March 2023 |
| Constituency1: | PR, SDP list |
| Predecessor1: | Seiji Mataichi |
| Successor1: | Yūko Ōtsubaki |
| Term Start2: | 26 July 2010 |
| Term End2: | 25 July 2016 |
| Constituency2: | PR, SDP list |
| Office3: | Member of the Oita Prefectural Assembly |
| Term Start3: | 2000 |
| Term End3: | April 2010 |
| Birth Date: | 7 March 1956 |
| Birth Place: | Usuki, Ōita, Japan |
| Party: | CDP |
| Otherparty: | SDP (until 2020) |
| Alma Mater: | Kyushu University |
[1] is a Japanese politician and former member of the House of Councillors from the proportional representation constituency. He was elected twice, in 2010 and in 2019. He previously served as an Ōita prefectural assembly member.
He ran for the Chairmanship of the Social Democratic Party (SDP) and defeated Tokyo City Toshima Ward Councilor Taiga Ishikawa, the first openly gay SDP elected politician, by a vote of 9,986 to 2,239 to win the party election on 14 October 2013. He was inaugurated on 26 October 2013 as SDP party leader.[2]
After a disappointing result in the 2016 upper house election, he announced his resignation as head of the party.[3] He eventually retracted his resignation after the party urged for him not to resign.[4] Yoshida concluded his term as president on 25 February 2018.[5] Yoshida is planning to run again for elected office in the future.[6]
On 24 December 2020, Yoshida submitted a notice of withdrawal to the Social Democratic Party and a notice of admission to the Constitutional Democratic Party (CDP), both of which were accepted on the same day.[7]
In March 2023, he resigned from his proportional seat in the House of Councillors to become a candidate in the April by-election for the Ōita majoritarian seat in the 2019 class. As CDP-nominated candidate with JCP and SDP support, he narrowly lost to government candidate Aki Shirasaka (LDP - Komeito) by 341 votes.[8] [9]