Kenta Izumi (泉 健太, Izumi Kenta; born 29 July 1974) is a Japanese politician who served as leader of the Constitutional Democratic Party of Japan (CDP) from 2021 to 2024. He is also a member of the House of Representatives in the National Diet, currently for the Kyoto 3rd district. He was first elected in 2000 under the Democratic Party of Japan. He served as Parliamentary Vice-Minister of the Cabinet Office from 2009 to 2010. After that, he served as chairman of the National Diet Measures Committee and Political Affairs Research Chairman of the Kibō no Tō, the Democratic Party for the People, and the Constitutional Democratic Party of Japan.

Izumi was born in Sapporo, Hokkaido, and was raised in Ishikari. After graduating from junior high and high school, he attended Ritsumeikan University Law School. While in university, he began to assist Kazunori Yamanoi, and, in 1996, when the Democratic Party formed, served as permanent secretary inside the Kyoto Prefecture. When he graduated from university in 1998, he became Tetsuro Fukuyama's secretary.

He ran as a candidate in the 2000 election for Kyoto-3, but lost, and did not win a seat proportionally. He ran again in 2003 election, and won. During the Democratic Party of Japan government's from 2009-2012, he served as Parliamentary Vice-Minister of the Cabinet Office and was in charge of the Administrative Reform Council. Although he lost his seat both in 2003 election and 2014 election, he won a seat proportionally both times, and won a by-election for the seat in 2016. When the Democratic Party split in 2017, he joined Kibō no Tō, where he served as the chairman of the National Assembly Committee from 2017 to 2018. In the Democratic Party for the People, which formed from a merger of Kibō no Tō and the Democratic Party, he served as the chairman of the National Assembly Committee in 2018 and the chairman of the Political Affairs Research Committee from 2018 to 2020.

In 2020, following the merger of the DPP into the CDP, he ran for leadership, but lost to Yukio Edano. He then became the party's Political Affairs Research Chairman. When Edano resigned as party leader following the results of the 2021 election, Izumi ran again in the leadership election and won, defeating Seiji Osaka and others to become party leader. Izumi formed the CDP's 'Next Cabinet' in September 2022 and became the shadow Prime Minister.

Izumi was born on 29 July, 1974, in Sapporo, Hokkaido. Izumi's family was self-employed in a ranch-related business. His father, Norio (Who died in 2011 at the age of 74), served as the neighborhood chairman, and later as a member of the Ishikari City Council. According to Kenta, his father was a conservative person, but when Kenta himself ran for the House of Representatives in 2000, his father switched to the Democratic Party of Japan.

Izumi lived in Izumi lived in Tonden, Kita-ku, Sapporo until he was about three years old, and then moved to Ishikari, where he lived until high school. His father was vocal about his own political opinions, and Izumi began to become curious about politics and elections in elementary school. After graduating from elementary school, Izumi entered Hanagawakita Junior High School. In junior high school, he belonged to the baseball club and served as the student council president. After graduating from junior high, he was planning to go to Sapporo Kita High School, but after seeing that Hokkaido Sapporo Kaisei High School participated in the Japanese High School Baseball Championship, he attended Kaisei instead. In high school, he again served on the baseball team and acted as student council president.

After graduating from high school, he entered the Ritsumeikan University School of Law. When he returned to Hokkaido during the summer vacation after his first year at university, a rally was held for the "New Wind Hokkaido Conference"; it was established by Takahiro Yokomichi, who served as Governor of Hokkaido, in preparation for his return to national politics. Izumi pointed out to Yokomichi the lack of young people at the rally. According to Izumi, about two days later, Yokomichi called his parents house, asking if he could speak with Izumi. This began his serious connection to politics. When Izumi returned to Kyoto for university, he visited the Japan Socialist Party Kyoto Prefectural Federation, but was told by executives there he had no future inside the party. Thereafter, he began assisting Kazunori Yamanoi, a lecturer at Ritsumeikan, with his political activities (Yamanoi would go on to become a representative of the Democratic Party). Yamanoi also introduced him to Tetsuro Fukuyama.

When the Democratic Party formed in 1996, Izumi served as permanent secretary of the Democratic Party in the Kyoto Prefecture. During the Kyoto mayoral election held in the same year, he organized a lecture event inviting candidates to speak. He was in the debate club at Ritsumeikan, and also served as President of the "Student Speech and Debate Exchange Group", a cross-university debate club. During the Nakhodka heavy oil spill accident, which was a result of a Russian taker crash off the coast of the Oki Islands, he chartered two buses to assist in the recovery effort and volunteered in heavy oil cleanup. He also worked as a staff member for an environmental NGO at the COP3 event held in the same year.