| Kotaro Nagasaki | |
| Native Name Lang: | ja |
| Term Start: | 17 February 2019 |
| Predecessor: | Hitoshi Goto |
| Office1: | Member of House of Representatives |
| Term Start1: | 11 September 2005 |
| Term End1: | 21 July 2009 |
| Constituency1: | Southern Kanto Block |
| Term Start2: | 8 December 2012 |
| Term End2: | 28 September 2017 |
| Constituency2: | Yamanashi 2nd ward |
| Birth Date: | 18 August 1968 |
| Birth Place: | Tokyo, Japan |
| Party: | Liberal Democratic Party |
| Alma Mater: | Tokyo University |
| Website: | Official website |
is a Japanese politician serving in the House of Representatives in the Diet (national legislature) as a member of the Liberal Democratic Party. A native of Tokyo and graduate of the University of Tokyo he joined the Ministry of Finance in 1991. He graduated from Cornell Law School in the United States while still in the ministry. In 2005 he left the ministry and was elected to the Diet for the first time. In 2019 he was elected governor of the Yamanashi Prefecture with 49.7% votes in a single round.