Italian serial killer or killers who murdered at least 16 people in the hills outside Florence between 1968 and 1985. The case inspired Thomas Harris's novel Hannibal (1999).

In 1968 a man and a woman were murdered in a parked car near Florence by a mysterious killer whom the Italian media later dubbed Il Mostro di Firenze (“The Monster of Florence”). Although the husband of the female victim was convicted of the crime and sentenced to 14 years in prison, other couples continued to be murdered after his confinement. In 1974 the killer attacked another couple, this time mutilating the body of the female victim. Two couples were murdered in similar fashion in 1981, and during the next four years four more couples were killed. Public fear was intensified by the extremely gruesome nature of the crimes. The killings stopped in 1985.

In 1994 Pietro Pacciani, an itinerant farm labourer, was convicted of murdering seven of the eight couples. Pacciani's conviction was overturned, however, and a new trial was ordered. Police then began to suspect that the crimes had been committed by a group led by Pacciani, but he died before the second trial could begin. Subsequently two of his alleged accomplices were convicted of the murders.