Kōdai Sakai is a Japanese voice actor born on September 30, 1986, in Kurume, Japan. His inspiration to pursue a career in voice acting came from watching Rika Matsumoto perform the role of Ash Ketchum in the Pokémon series. Initially working as a salaryman, he eventually left his job to follow this ambition and was hired by the talent agency Early Wing, making his voice acting debut in 2013 with a small role in the series Karneval. His first lead role came in 2016 with the anime The Lost Village, where he voiced the character Mitsumune.

Sakai has built a diverse portfolio of roles across various anime series. He is known for playing Sakuya Sakuma in the A3! series, a role he performed in both the Season Spring & Summer and Season Autumn & Winter installments. He also voiced Shaun, a character also known as John, in the series Shadows House. In the long-running sports franchise Captain Tsubasa, he took on the role of Teppei Kisugi. His other notable anime roles include Nobunaga Oda in Nobunaga Teacher's Young Bride, Yūto Suoh in The Master of Ragnarok & Blesser of Einherjar, Shun Imai in Odd Taxi, and Medoki in The Vampire Dies in No Time. More recently, he was cast as Haruto Atori in the 2025 anime adaptation of the Tasokare Hotel game.

In recognition of his work, Sakai received the Game Award at the 14th Seiyu Awards in 2020. He continues to be active in the industry, with ongoing and new roles in various anime productions.