Kōichi Sōma is a Japanese voice actor born on February 5, 1982, in Saga Prefecture. He is 170 cm tall with blood type A. His interest in voice acting began in childhood, inspired by dubbed foreign films and anime magazines. After graduating from the Pro-Fit Voice Actors' Training School, he began his professional career in the mid-2000s. Following the closure of his longtime agency Pro-Fit's management operations at the end of March 2022, he moved to Raccoon Dog, where he continues his career.

Sōma is a prolific voice actor known primarily for his work in supporting and character roles across a wide range of anime television series. He is frequently cast as authority figures, soldiers, villains, townspeople, and monsters, providing depth to the worlds of numerous shows. His filmography includes a mix of long-running franchises and seasonal anime.

He has voiced several characters in the Gundam franchise, including roles in Gundam Build Divers and a more prominent role as Jirik in Gundam Build Divers Re:RISE. In the series Shinobi no Ittoki, he voiced the character Benkei-Musō. He took on monster roles in Sleepy Princess in the Demon Castle, playing both Frankenzombie and Ghost Wrapping Paper. His role as Kachō, the chief manager, in the short-form anime Tawawa on Monday represents his work in more grounded, contemporary settings, and he voiced Captain Soolu in Monster Strike: Mermaid Rhapsody.

Other notable roles include appearances in major series such as JoJo's Bizarre Adventure: Golden Wind, Dr. STONE, One Punch Man, and That Time I Got Reincarnated as a Slime. He has also been part of the casts for Teasing Master Takagi-san, Laid-Back Camp, and SPY x FAMILY. In addition to animation, his recent work includes roles in video games and dubbed narration.