is a Japanese family name.
It may describe one of several Koizumi railway stations.
It can refer to a number of people, including the following members of the prominent Koizumi family:
- , former prime minister of Japan
- , a second-generation Diet member and the father of Junichiro Koizumi
- , Japanese politician and the father-in-law of Junya Koizumi
- , an aspiring actor and the first son of Junichiro Koizumi
- , a fourth-generation Diet member and the second son of Junichiro Koizumi
Other individuals
- Ariane Koizumi, American fashion model and actress
- , Japanese poet
- , a Japanese beach volleyball player
- , the founder of British Judo
- , Japanese racing driver
- , Japanese footballer
- , singer and actress
- , Japanese model
- , film director
- Patrick Lafcadio Hearn or , Irish-Greek-Japanese author
- Koizumi Setsuko (小泉節子, 1868–1932), wife of Lafcadio Hearn
- , video game designer
- , Japanese footballer
Fictional characters
- Koizumi, character in Ms. Koizumi Loves Ramen Noodles
- Akako Koizumi, character in Magic Kaito
- Asami Koizumi from the Young Justice animated series
- , character in Haruhi Suzumiya series
- Mika Koizumi, character in Choudenshi Bioman
- Risa Koizumi, the protagonist of Love Com
- Several characters in Guru Guru Pon-chan, Ponta, Yuki, Soichiro, and Ji Koizumi
- Mahiru Koizumi, a character in Danganronpa 2: Goodbye Despair
- Hanayo Koizumi, a character from [Love Live!]
- Natsumi Koizumi, a character from School Days
- Yoshiko Koizumi, a main character girl from Little Ghost Q-Taro
See also
- , botanist whose standard abbreviation in botanical works is Koidz.