| Mitsunori Okamoto | |
| Native Name Lang: | ja |
| Office: | Member of the House of Representatives |
| Constituency: | Aichi 9th |
| Term Start: | 29 October 2024 |
| Predecessor: | Yasumasa Nagasaka |
| Constituency1: | Tōkai PR |
| Term Start1: | 19 December 2014 |
| Term End1: | 14 October 2021 |
| Constituency2: | Tōkai PR (2003–2009) Aichi 9th (2009–2012) |
| Term Start2: | 9 November 2003 |
| Term End2: | 16 November 2012 |
| Predecessor2: | Multi-member district |
| Successor2: | Yasumasa Nagasaka |
| Birth Date: | 18 June 1971 |
| Birth Place: | Yōkaichi, Shiga, Japan |
| Alma Mater: | Nagoya University |
| Party: | CDP |
| Otherparty: | DPJ DP Kibō no Tō DPP |
is a Japanese politician of the Constitutional Democratic Party, who is a member of the House of Representatives in the Diet (national legislature). A native of Yōkaichi, Shiga and graduate of Nagoya University, he obtained his medical license in 1996 and received his Ph.D in medicine from Nagoya University. He was elected to the House of Representatives for the first time in 2003. He was defeated in the 2005 election. He ran again to the House of Representatives in 2009 in the 9th district of Aichi defeating Prime Minister from 1989 to 1991, Toshiki Kaifu in a stunning upset.
After losing his seat and being in 6th of 5 elected candidates for the CDP in the Tōkai proportional representation block during the 2021 election, he won a constituency in 2024, defeating Yasumasa Nagasaka in Aichi 9th district.