Tetsuya Asado was a Japanese voice actor and actor born on July 25, 1935, in Yokohama, Kanagawa Prefecture, Japan. He passed away on November 15, 2018. His real name was Masaaki Asado, and he was a member of the theater company Theador Eco, which he joined in March 1995. Early in his career, he also worked under the stage names Junichi Yumikawa and Yuu Minami Yoshino. He was married to fellow voice actress Mariko Mukai, known for dubbing Marilyn Monroe.

Asado's career spanned a wide range of work in television animation, tokusatsu, and foreign film dubbing. In anime, one of his notable roles was as Rudolph in the 1969 series Tiger Mask. He also voiced the character Isao Egawa in the 1971 television series Nozomi in the Sun. Later, he took on the role of Lieutenant General Saint Clair Celebret in the Legend of the Galactic Heroes OVA series.

His voice was frequently heard in tokusatsu productions. He provided voices for various monster characters in the Kamen Rider franchise, including Kamen Rider (Skyrider) and Kamen Rider Super-1. He also had a recurring role as the voice of Monster Uncle in the Toho superhero series Go! Godman and its 1972 film version. In the sequel series Go! Greenman, he served as the program's narrator or commentator. Asado also appeared on camera in the children's program Ohayou! Kodomo Show, where he was known as "Kaiju Oji-san" (Monster Uncle) and explained kaiju to children.

In addition to his Japanese-language voice work, Asado was active in dubbing foreign films and television series. His dubbing credits include the role of Apon in Aliens, Forrestal in Commando, Jim in Beverly Hills, 90210, and Harry Ellis in Die Hard.