Ginzō Matsuo was a Japanese actor, voice actor, and narrator born on December 26, 1951, in Nakatsu, Oita Prefecture, Japan. His real name was Kōichi Matsuo. He stood 163 centimeters tall and had blood type O. Matsuo graduated from the Faculty of Letters at Rissho University. Before entering the voice acting industry, he worked as a stage actor with troupes such as Gekidan Kai and Gekidan Seito. He also held jobs as a bartender and wrote songs for commercials. His professional voice acting career began in the 1980s after he joined the agency Aoni Production. In 1997, he left to establish his own agency, Gin Production, where he served as the first president.

Matsuo became widely recognized for his versatile performances, often portraying comedic supporting characters as well as authoritative figures. He was known for providing voices for numerous anime series produced by Toei Animation, Shin-Ei Animation, and Sunrise. Among his most notable roles were Hemu Hemu in the long-running series Nintama Rantarō and Ginnosuke Nohara, the grandfather of the titular character in Crayon Shin-chan. He also voiced Captain Smoker in One Piece, a role he performed from the character's introduction in 1999 until his death.

Throughout his career, Matsuo amassed an extensive list of credits. He played Kuwagata in Inspector Fabre (also known as Mushi Hakase), Danbei in both Cutey Honey Flash and its film version, and Miguel in Macross 7 the Movie: The Galaxy's Calling Me!. In the Digimon franchise, he voiced TonosamaGekomon in the first two Digimon Adventure series and portrayed Wataru Urazoe in the film Digimon Tamers: Battle of Adventurers. His other prominent roles included Taizo Kotobuki in Super GALS!, Alexander T. Oyajiide in Ojamajo Doremi, and Kagome's grandfather in InuYasha. He was also the voice of Sha Wujing in Funky Fables and provided voices for the film Sword for Truth, the series Jungle Emperor Leo, and many others such as Billiken, Shakotan Boogie, Kinkyū Hasshin Saver Kids, Ultraman Company, and Jigoku Sensei Nube.

Ginzō Matsuo passed away on August 25, 2001, at the age of 49 due to an acute subarachnoid hemorrhage. His sudden death was attributed to overwork and a demanding schedule that involved managing his agency while continuing to perform regularly. Following his passing, several of his major roles were recast with other voice actors, including Mahito Ōba (as Smoker in One Piece), Chō (as Ginnosuke Nohara in Crayon Shin-chan), and Bin Shimada (as Hemu Hemu in Nintama Rantarō).