Kenji Yamauchi is a Japanese actor and voice actor born on September 23, 1972, in Kyoto, Japan. He is a graduate of the Seinenza Theater Research Institute, where he completed a two-year training program, and his career began in theater before expanding into on-screen and voice acting roles. He is currently affiliated with the talent agency Kenyu Office.

Yamauchi has built a career that spans live-action television dramas and films, as well as a extensive voice acting portfolio in anime, video games, and dubbing Western productions. His live-action appearances include roles in the 2001 film Godzilla, Mothra, King Ghidorah: Giant Monsters All-Out Attack and the 2012 drama Tokyo Airport Air Traffic Control Security Department.

In anime, Yamauchi has voiced a wide array of characters across numerous popular series. He is known for several notable roles, including Sima Yi Destiny Gundam in SD Gundam World Heroes and Sōgyoku in the Shinkansen Henkei Robo Shinkalion franchise, appearing in Shinkalion the Animation, Shinkalion: Mirai Kara Shinsoku no ALFA-X, and Shinkalion Z. He also voices Arthur von Streit in Legend of the Galactic Heroes: Die Neue These Second and Legend of the Galactic Heroes: Die Neue These - Collision. Other significant anime voice credits include roles in long-running and hit series such as Naruto Shippūden as Harusame, Attack on Titan as a Captain and Corps Executive, My Hero Academia and its film Heroes Rising as a Public Safety Commission Executive, Chihayafuru as Kazumitsu Komine, Blue Exorcist: Kyoto Saga, Cop Craft as Gordon, Those Snow White Notes as Toraji Yamano, and Princess Connect! Re:Dive as the Elder.

His work is characterized by a deep and dynamic voice that allows him to portray a range of character types, from villains to mentors. Beyond anime, his voice acting skills are in demand for dubbing Western films and television series into Japanese, with credits including Altered Carbon: Resleeved as Hideki Tanaseda and various roles in shows like Superman & Lois and Gotham. He has also provided voices for major video game titles such as Final Fantasy VII Remake and The Elder Scrolls V: Skyrim.