Junichi Takeoka is a Japanese actor and voice actor born in Tokyo on February 25, 1955. He began his performing career at the age of ten, joining a theater group and later becoming a member of the Tokyo Ichigumi Theater Company, where he remained until its dissolution in 1995. His early work included appearances as a child actor in NHK television dramas such as Tabiji and Aiueo during the late 1960s, and he continued to build a career in television throughout the 1970s and 1980s with roles in popular series like Taiyo ni Hoero and Ore-tachi no Tabi. He also appeared in the 1975 film Zessho.

In addition to his on-screen work, Takeoka developed a significant career in theater, performing in musicals and stage productions at prominent venues including the Imperial Theatre and the New National Theatre of Tokyo. His stage credits include productions of Me and My Girl and Mozart. He also lent his voice to various radio and CD dramas, with notable roles in adaptations of Banana Fish and Kamui Gaiden.

Takeoka's voice acting work in anime includes several key roles. He is recognized for providing the voice of Raiji Hikata in the series Thunderbirds 2086, also known as Techno Voyager. He voiced the character Ken in Moby Dick Five and Lieutenant Schneider in the 1996 television series Rurouni Kenshin. He also had a role in the 1980 Astro Boy television series.

One of his notable anime film roles is that of Rock Nasenkopf in the 1979 television film Undersea Super Train: Marine Express. In this Osamu Tezuka production, he voices the adopted son of the train's inventor, Dr. Nasenkopf, who serves as the driver of the Marine Express on its ill-fated maiden voyage. The character of Rock was a departure from his usual villainous roles in Tezuka's works, being cast as a hero for this story. His character's journey ultimately leads him to remain in the ancient kingdom of Mu as the consort of its queen.

Throughout his career, Takeoka has been affiliated with several acting companies, including Meijiza Art Create and a company called Minna no S, and has worked as a freelancer. He is known for his versatility as a performer, with a career spanning television, film, theater, and voice acting that began in his childhood.