Tomomitsu Yamaguchi is a Japanese entertainer whose career encompasses comedy, acting, singing, and voice acting. Born on March 14, 1969, in Osaka, he is widely recognized as a television personality and one half of the comedic manzai duo DonDokoDon. His voice acting work, while not his primary occupation, includes several notable roles in anime films and dubbed productions.

Yamaguchi's entry into the entertainment industry followed a brief period as a business worker. He left his job to pursue a career as a singer, which eventually led him to variety shows and comedy. His rise in popularity was bolstered by regular appearances on programs such as Waratte Iitomo, leading to a diverse career in front of the camera.

In the realm of anime, Yamaguchi has contributed his voice to a range of characters, often in film adaptations. In 2004, he voiced the character Ryo in the acclaimed animated film Mind Game. The following year, he took on the role of Kentaro Mirai in the film Kouchuu Ouja Mushiking: Greatest Champion e no Michi, a role based on the popular arcade game and media mix. He also participated in the 2007 omnibus film Genius Party, providing voice work for one of its segments, Deathtic 4. In 2011, Yamaguchi was a guest voice actor for the 3D CGI film One Piece 3D: Mugiwara Chase, where he voiced three characters: the old pirate Schneider, his dog Schneider, and a Steller's sea eagle.

Beyond original anime productions, Yamaguchi has also performed voice work for Japanese dubs of foreign films. A prominent example is his role as the voice of Mater, the tow truck, in the Japanese-language version of the Cars franchise, including the.

His collaborations in voice work are typically project-based, stemming from his broad career as a celebrity talent rather than recurring partnerships with specific anime directors or studios. While his filmography is extensive in live-action television and film, his voice acting credits, though varied, are fewer in number and often tied to his status as a well-known public figure.