| Koichi Kato | |
| Native Name Lang: | ja |
| Office: | Member of the House of Representatives |
| Constituency: | Tokyo 20th (2000–2005; 2009–2012) Tokyo PR (2005–2009) |
| Term Start: | 2000 |
| Term End: | 2012 |
| Predecessor: | Yuriko Ono |
| Successor: | Seiji Kihara |
| Birth Date: | 6 April 1964 |
| Birth Place: | Chiyoda, Tokyo, Japan |
| Party: | Democratic |
| Alma Mater: | Sophia University |
is a Japanese politician from Tokyo and a member of the Democratic Party of Japan. A native of Chiyoda, Tokyo and graduate of Sophia University, he worked at Recruit from 1988 to 1996. Kato was elected to the House of Representatives for the first time in 2000 and served until 2012.