Toshio Oka is a lyricist who composed the lyrics to several anime theme songs, primarily during the late 1960s, the 1970s, and the early 1980s. He was born in Fukushima Prefecture in 1917, under the name of Yasukichi Nishiyama. Oka studied under the poet Yaso Saijo at the age of 18. In 1942, around the end of World War II, he began working as a reporter for a newspaper called the Mainichi Shimbun.

In 1949, Oka started working as a lyricist for Nippon Columbia (which is now known as Columbia Music Entertainment). He wrote "Koukou Sannensei" for singer Kazuo Funaki. In 1963, this song helped Oka to earn the Lyricist Award at the Japan Record Awards. He also wrote "Akogare no Yubin Basha" and "Kougen Ressha wa Iku" for composer Yuji Koseki, and "Tokyo no Bus Girl" for composer Gento Uehara.

Oka has also worked with Chiyoko Shimakura and Kanae Wada. For Chiyoko Shimakura, his lyrics appear on these releases: Chiyoko Shimakura Zenshu (50th Anniversary), Shin Natumero Zenkyokushu Part 1, Shin Natumero Zenkyokushu Part 2, and Showa Kokumin Teki Hit2. With Kanae Wada, Oka composed music for for Onnanoko Muki, Shudaika no Ayumi, Natsukashi no Bmen, Kurenai Sanshiro ("The Man in the Sunset"), Kabatotto ("Ippo Thomas"), and Kumiko Kaori Super Best. In 1973, Oka compsed the lyrics to the opening and closing theme songs for Kerokko Demetan ("Kerokko Demetan" and "Makeru na Demetan"). Some of Oka's work also appears on the 40th anniversary CD box set from anime singer Ichiro Mizuki. His work has also appeared on compilation albums in Japan (such as Whole-Tone Pop Songs Complete Works 15 and Whole-Tone Pop Songs Complete Works 19).

Oka's anime lyrics from the 1970s begin in 1970, for a song from Hakushon Daimaou ("The Song in Hakushon Daimaou"). In 1972, Oka composed the lyrics for songs from Kashi-No Ki Mock ("Boku wa kanashii ki-no ningyo") and Umi no Triton. In 1973, he composed the theme song lyrics for Shinzo Ningen Casshan ("Tatakae! Casshan" and "Are wa Shinzo Ningen"). In 1979, Oka composed the lyrics for the theme songs for Science Ninja Team Gatchaman Fighter, which is also known as Gatchaman F ("Gatchaman Fighter" and "Bokura no Gatchaman"). His last known anime lyrics are for 1980's Tondemo Senshi Muteking.

Sadly, Toshio Oka passed away on November 24, 2009 at a Tokyo hospital from renal failure. He was 92 at the time of his death.