He was born in Pisa.
In November 1968, he moved to Parma, where he still lives with his wife Caterina.
After finishing high school, he enrolled at 'DSU[disambiguation needed], the faculty of Geology, another experience that marked him deeply. While at university, Ortolani draws his characters first, and the theme of geology became a catchphrase of the first issues of his major work, Rat-Man.
In 1989 endured the publishing house Comic Art two stories: the tragic and the other comic. The publisher Rinaldo Traini published the comic story on the second Spot (supplement of Eternauta dedicated to beginners), marking the Birth of Rat-Man.
The shocking origins of Rat-Man earned him an Ortolani the award for best newcomer to the writer Lucca Comics of 1990. With visibility gained, Leo began to collaborate with magazines and fanzine independent.
For the fanzineMade in USA created two more stories starring Rat-Man ( Topin! The Wonder Mouse! And From the Future) and several parodies of superheroes (including X-Men, Fantastic Four and Superman).
The most important works of this cycle are the four stories about Fantastic Four, as an ideal continuation (parodied) the work of Jack Kirby. Kirby stopped drawing Fantastic Four with the number 102: Ortolani realized the numbers 103-106, completely upsetting the group.
Called to military service in 'Air Force, Ortolani drew inspiration from life in the barracks gathering their experiences in a detailed diary that became the initial starting point for The last rookie, a series strips on military life (the same as the protagonist Ortolani) which were then published as an appendix to Storm Trooper.
During this period, Ortolani also collaborated in Starcomìx humor magazine directed by Luca Boschi and published by Star Comics in Totem Comic and Totem Extra, where he made The impervious, Clan, The wonder of nature and The wonders of technology. In this period he also strips the series Those of Parma, published in the Gazzetta di Parma, speaking of the city of Parma and its inhabitants, a selection of which was collected in the volume Editions Bands Dessinée.
The short stories of the series of Wonderland were then taken years later, collected in three volumes by Panini Comics.