Mizuki was born in Setagaya, Tokyo. In July 1948, he signed to the Nippon Columbia label and released his first single called "Kimi ni sasageru Boku no Uta", composed by Kanae Wada. In 1971, Mizuki recorded the song "Genshi Shōnen Ryū ga Yuku" which was used as the opening theme for Genshi Shōnen Ryū. This began his foray into recording well over 1200 songs for various soundtracks as well as original singles and albums. Other early songs sung by Mizuki include the themes to Chojin Barom 1, Mazinger Z, Babel II, Robot Detective, Kamen Rider X, Great Mazinger, Ganbare!! Robocon, Kamen Rider Stronger, , Steel Jeeg, Akumaizer 3, Chōdenji Robo Combattler V, and Space PirateCaptain Harlock. His extensive discography in the 1970s led to his dubbing as "Aniking and the "Emperor of Anime Songs", with whom Mitsuko Horie is the "Queen" and Hironobu Kageyama is the "Prince". Mizuki is also part of the judging panel at the Animax Anison Grand Prix, with Horie and Yumi Matsuzawa. Mizuki performed theme songs throughout the 1980s and 1990s, for shows such as Beast King GoLion, Getter Robo Go, and Jikuu Senshi Spielban, his work not as extensive until 2000. On July 17, 2000, with fellow anison vocalists Hironobu Kageyama, Masaaki Endoh, Eizo Sakamoto, and Rica Matsumoto, he formed the "supergroup" JAM Project. He later reduced his membership in the group to "part-time", allowing for the entry of Hiroshi Kitadani, Masami Okui, and Yoshiki Fukuyama. He would return to recording in 2007 with his performances on the soundtrack of Juken Sentai Gekiranger, singing its ending theme "Tao", an image song "Chikai", and on another image song "Burning up! ~Jōnetsu o Uketsui de~" performed as a duet with Takayoshi Tanimoto who sang the series' opening theme. He also sang on JAM Project's single "STORMBRINGER", the opening theme for Kotetsushin Jeeg, a sequel to Steel Jeeg. In 2008, he released his 40th anniversary Ichirou Mizuki: Newest Best album, the Michi ~road~ 5-CD box set including 216 songs from his discography, and the TV Size Best album. Other recent releases by Mizuki include two singles for Chōjin Neiger, a local hero from Akita Prefecture. His most recent work is a single for the OVA adaptation of Katte ni Kaizō, with its theme song "Katte ni Kaizō Shite mo Ii ze", and an insert song, called "Nuiguruma", featuring Kenji Ohtsuki.
Television
In addition to his career as a vocalist, Mizuki has been cast in several roles as both a voice actor and a live-action actor. As a voice actor, he played the roles of Yoldo in the first episode of the OVA Dangaioh, Rat Hector in Coral no Tanken, and the villain Keisar Ephes in the video gameSuper Robot Wars Alpha 3. His live-action roles include Dr. Ben in Jikuu Senshi Spielban and VoiceluggerGold in Voicelugger, a Tokusatsu show based on the last concept written by Shotaro Ishinomori before his death. He also made a guest appearance on the Japanese comedytelevision show, Gaki No Tsukai. He voiced the title characterBobobo-bo Bo-bobo in the first PlayStation 2 game of the series, as well as singing the theme song. In 2010, he had a role in an episode of arc of Kamen Rider W along with fellow musicians Aya Kamiki and TAKUYA. In 2012, he starred in one of the episodes in Tokumei Sentai Go-Busters as well as singing "Li-Oh! Kenzan Champion!" which is a theme song for the new robot introduced in the episode. His voice is also used as the voice for the robot's control system.