Liliana Fantoni came from an artistic family - she has cooperated a lot with her father Guido and her brother Mario. She made her debut in Modellina, the children's supplement of the magazine Modella. She then made the adventure serials 'Le Avventure di Straccetto' and 'La Banda dagli Speroni d'Argento' for the comics paper Giornale dei Ragazzi from Naples in the period 1944-1946. After World War II, she then went to work as her father's assistant. In 1953, she drew the fairy tale 'Gianforte' from a script by Giuseppe Madonia, which was published in Collana del Trifoglio at Bonelli's Casa Editrice Audace. She also made fairy tale comics for the Dardo publications Chicchirichì and Crì Crì in the early 1950s.
Liliana teamed up with her brother Mario to produce comic books for Dardo about the reporter 'James Taylor, il reporter giramondo' and about the Indian 'Gessy l'Indian Agent' in 1952. Brother and sister Fantoni then joined their father Guido Fantoni in a joint production of 'Capitan Walter' stories for Anonima Veritas Editrice in Rome from 1953 to 1957. The family continued their collaboration in the magazine Il Vittorioso with the stories 'Calcio in costume' and 'Il figlio del gangster'. After the death of Guido in 1957, Liliana and Mario created 'Il sostituto', 'Il caso Elvy' and '30° piano' together. In the related album series 'Jolly', they made the serials 'Hoka Hey' (script Danilo Forina), 'Le Terre Insagnuinate' (script Renata De Barba), 'Il Gran Premio Siepi' (script Piero Salvatico), 'L'arcipelago della Copra' (with Sandro Cassone) and 'Il progretto Stella Azzurra' (script Mario Basari).
Liliana retired from the comics industry in the early 1960s and focused on her family life, while Mario spent the next ten years working in his family's artistic ceramics workshop. Liliana illustrated Tommaso Landolfi's novel 'Il principe infelice' in 1985.