Ryouichi Tanaka is a veteran Japanese voice actor, narrator, and actor born on January 26, 1947, in Tokyo. He is affiliated with Aoni Production, a major talent agency he has been with for the entirety of his long career. His late younger brother, Kazumi Tanaka, was also a voice actor affiliated with the same agency.

Tanaka's career began in 1970 and spans over five decades, during which he has demonstrated considerable range, voicing characters from rebellious young men and villains to serious middle-aged men and elderly figures. One of his most iconic early roles was as the titular character Akira Fudo, also known as Devilman, in the 1972 television anime Devilman. Another long-running and beloved role is that of Nobita's teacher, known as Sensei, in the Doraemon franchise, a part he played for over 24 years from 1981 to 2005, including many of the theatrical features.

He has been a regular presence in numerous classic anime series. In the world of sports and fighting anime, Tanaka voiced Kentaro Takaoka, also known as the Yellow Devil, in the original 1970 Tiger Mask, a role he reprised decades later in the 2016 series Tiger Mask W. He was the first voice of the cyborg wrestler Warsman in the original Kinnikuman anime and also voiced the character Prisman in the series Kinnikuman: Kinnikusei Ōi Sōdatsu-hen. He also lent his voice to Kurotora in Ginga Nagareboshi Gin and Shingo Tamai in Akakichi no Eleven.

Tanaka has also been a prominent figure in the mecha and superhero genres. His credits include Rocky Andor in Fang of the Sun Dougram, Brainstorm in Transformers: The Headmasters, Lander in Transformers: Super God Masterforce, and Kamen Rider V3 in the animated feature Kamen Rider SD. In the long-running Saint Seiya franchise, he is a regular performer, most notably as the villainous Cancer Deathmask. A more recent role is Warden Michael Halls in the Baki Hanma series.

Beyond animation, Tanaka's work extends to dubbing foreign films and television series for Japanese audiences, as well as voice work in tokusatsu superhero productions and video games. His extensive and diverse filmography solidifies his status as a highly respected and talented figure in the Japanese voice acting industry.