Franco Oneta was born in Casalbuttano and began in the comic field at the early age of 15 in 1949. His first work was for the Milanese publisher Pasquale Giurleo, drawing the character 'Trottolo', that later became 'Trottolino' when published by Bianconi. He cooperated with Messaggero dei Ragazzi between 1958 and 1964, illustrating series like 'Spiritello', 'Anacleto', 'Pallino', 'Giuggola e Lenticchia' and 'Robin Poot'. For adventurous comics, he cooperated with the publishing house Casarotti, where he worked alongside Pietro Gamba on 'Billy Rock'. He contributed stories to the weekly magazine Jolly for AVE, and he drew 'Capitani Coraggiosi', 'I Ragazzi della via Paal' and humorous stories like 'Gendarme 00' for Esploriamo of Editrice la Scuola.
In 1963, he began a long cooperation with the French publisher Lug, that was based in Lyon. He provided artwork for a great many series, including 'Petit Scout', 'Galaor', 'Zurm', 'Frank Universa', 'Stuntman', 'Bozart' and 'Mustang'. His most notable work for this publisher is however the jungle series 'Zembla', of which he has illustrated over 200 episodes. He also made a comic based on the animation series 'Oum le Dauphin Blanc' for Lug. His brother Fausto Oneta has cooperated with him on several of these serials, that were published in Italy under the title 'Zum il delfino bianco' by Edigamma.
Oneta is probably best-known for his many contributions to Il Giornalino of the Gruppo Editoriale San Paolo, to which he was a loyal contributor from 1978. Oneta drew the adventure series 'Class Airport' and comics based on popular characters like 'Sherlock Holmes', 'Snorky', 'Foofur' and Hanna-Barbera's 'The Jetsons', 'The Flintstones', 'Yogi Bear' and 'Scooby Doo'. Three books with his 'Snorky' stories were published by the Belgian publisher Dupuis in the 1980s (scripts by Raoul Cauvin).
He drew the feature 'Diario G' for many years, and he also contributed educational drawings, biographies of famous football players, covers and a comic adaptation of the film 'The Pagemaster' to the Catholic children's weekly. For the audiovisual department of the magazine's publisher, he developed a CD-ROM about catechism for children.
Additional creations by Oneta are characters like 'Lilla', 'Leti e Mac Mac', 'Olivo lo sportivo' (in Il Piccolo Missionario by Ed. Piemme in Verona, 2002) and 'Don Sempronio' (for the Catholic women's magazine Madre). He has furthermore produced over 10,000 cartoons for the puzzle magazine La Settimana Enigmistica, advertising comics like 'Poochie e Robotix' for MB and drawings for the RAI ecology program 'Natura con rabbia e con amore'. From the mid-1970s, Oneta has participated in several (inter)national exhibitions.