Born in Brescia in 1967, Simeoni is one of the young authors (Rossi, Mutti, Olivares) who grew under the guidance of Rubén Sosa, and later created the series "Full Moon Project". After a professional stint in advertising, Simeoni becomes a full time comics author, working for “Full Moon Project”, "Lazarus Ledd" (Star Comics) and "Intrepido", by Editrice Universo. He’s one of the creators of "Hammer", a series that closes after its 13th issue; just like the other members of the “Brescia school”, Simeoni passes to Bonelli: his début is on Nathan Never’s pages, with episode n. 64, "L’isola nel cielo". He then works for Brendon (2001), Gregory Hunter (in 2002, he’s the writer and artist of the first Maxi Gregory Hunter) and Volto Nascosto (2007). Also in 2007, Simeoni is the author of text and art for "Gli occhi e il buio", the second issue of the series Romanzi a Fumetti Bonelli.