Terrorism in Italy is related to political and subversive terrorism activities, carried out by various groups and organizations with different and sometimes conflicting methods, motivations and interests. This article is primarily about late 20th-century and early 21st-century terrorism.

Since the late 1960s, terrorism became a more serious issue in Italy. In the early part of this period, it was known as "opposed extremisms", later the media renamed this period as the "Years of Lead," inspired by Die bleierne Zeit, or Anni di piombo, a film by German director Margarethe von Trotta that won the Golden Lion at the Venice Film Festival in 1981. The "Years of Lead" period ended at the close of the 1980s decade.

At the end of the 1990s, a fresh wave of political terrorism, consisting of severe yet sporadic episodes, broke out again in Italy. Episodes occurred until the early 2000s.

In addition to political terrorism, which was widespread during the Cold War to contribute to the "strategy of tension", Mafia-linked terrorism was active in Sicily. The main criminal organizations that operated in that period were the Cosa Nostra, Camorra, 'Ndrangheta and Sacra Corona Unita.

Several scholars have to analyze and understand the causes during the longlasting periods of terrorism. Italy has suffered more from such political terrorism than most other European countries, with the exception of Northern Ireland and the Basque Country in Spain. In the early 21st century, political scientist Ernesto Galli della Loggia analyzed the issue of the Italian peculiarity, concluding that Italian society is characterized by a trace of violence. This interpretation was controversial, with opinions arising on both sides.

Giovanni Fassanella and Giovanni Pellegrino also addressed the issue of terrorism in their book titled "La Guerra civile" (The Civil War), which explores the fact that Italy has been threatened by outbreaks of civil war, or terrorist events, for more than fifty years. This instability has prevented the normal development of Italy.

There has been widespread suspicion among some analysts that part of the Italian 1970s history was influenced by the activity of members of Secret services and extra Parliamentary political groups, which had their own interests in destabilizing the Italian political system and influencing political choices.

Terrorism did not succeed in overthrowing the state. The several Marxist–Leninist far-left groups were ultimately defeated, and their energy faded.