Koji Seki
- Born
- 25 November 1982 (43 years)
- Place of birth
- Saitama, Japan
- Gender
- Male
Koji Seki (関 幸司, Seki Kōji, born November 25, 1982) is a Japanese voice actor from Saitama Prefecture who is affiliated with Raccoon Dog. He graduated from Pro-Fit Voice Actor Training School and joined the agency Pro-Fit. On April 1, 2022, he transferred to Raccoon Dog.
