Toyoo Ashida was born on April 21, 1944. During his career in anime, he served as an animator, a designer, a director, and a producer. He worked on television series, movies, and OAVs.

He served as a producer on The Cosmopolitan Prayers television series, the Grenadier television series, and the Hit o Nerae! television series. Ashida also did production collaboration work on the Black Blood Brothers television series.

Ashida served as a director on Cho Bakumatsu Shonen Seiki Takamaru OAV, the Dr. Slump & Arale-chan Hoyoyo! Yume no To Mecha Police film, both of the Fist of the North Star television series and the Fist of the North Star film, the Gdleen OAV, the Kuso Kagaku Sekau Gulliver Boy anime series (which Ashida created), the Pink Mizu Dorobou Ame Dorobou film, the Shin Cho Bakumatsu Shonen Seiki Takamaru OAV, the Soten Koro television series, the Ultimate Teacher OAV, the Vampire Hunter D OAV, and The World of Narue television series.

He served as an animation director on the Bats and Terry film, the Farewell to Space Battleship Yamato film, the Jetter Mars anime series, the Mado King Granzort television series, the Maeterlinck's Blue Bird television series, the Manga Nihon Emaki television series, the Moomin television series, the New Moomin television series, the Space Battleship Yamato television series and film, the Space Warrior Baldios film, the Time Trouble Tondekeman! television series, the UFO Senshi Daiapolon television series, the Ulysseus 31 television series, and the Yatterman television series.

Ashida served as an animator on the Boken Gabotenjima television series, the Cleopatra film, the Inuyasha television series, the Kyoufu Densetsu – Kaiki! Frankenstein special, the Pokemon: Lucario and the Mystery of Mew film, and the Space Boy Soran film. He also did in-between animation for the Uchu Shonen Soran television series, as well as some storyboard work for the Oh! Edo Rocket television series. He also served as the art director for the Wansa-kun television series. Ashida also served as a character designer on the Cho Mashin Eiyuden Wataru television series, the Choriki Robo Galatt television series, the Crystal Triangle OAV, the second Cyborg 009 television series, the Delpower X Bakuhatsu Miracle Genki! OAV, the F-Zero Falcon Densetsu television series, the Fairy Princess Minky Momo: La ronde in my dream OAV, the Ginga Hyoryu Vifam television series and OAVs, two Mado King Granzort OAVs, two Mashin Eiyuden Wataru television series, two Minky Momo OAVs, and the second UFO Senshi Daiapolon television series.

Ashida founded Studio Live in 1976; while he was the studio's president, he became a mentor to a number of animators. He also co-founded the labor group Japan Animation Creators Association (JAniCA) in 2007, and served as the group's first president.

Sadly, Toyoo Ashida passed away on July 23, 2011 at the age of 67. His passing was reported by fellow animators Atsuko Watanabe and Hiroshi Koujina.