Marco Donat-Cattin (28 September 1953 – 19 June 1988) was an Italian terrorist. He was a founding member of Prima Linea far-left terrorist organization.
After having had a son when he was just 17 and later separating from the mother, he frequented the faculty of jurisprudence. In 1974 he found a job as library carer at a secondary school in Turin, where he met future terrorist Claudio Sandalo.
Starting from 1976, he participated in the establishment of Prima Linea, becoming a member of its national council. On 29 January 1979, he assassinated in Milan, together with Sergio Segio, judge Emilio Alessandrini. He was also one of the killers of a barman in Turin in the following July.
Thanks to the relevations of Prima Linea's pentito Roberto Sandalo, he was identified as one of the organizations' main members by the Italian police. Donat-Cattin was however able to escape to France. This caused a national scandal after his father, then vice-secretary of Democrazia Cristiana (the relative majority party in Italy at the time), was accused of having helped him to cross the frontier. Francesco Cossiga, another DC member who at the time was prime minister, was also suspected and underwent an official inquiry of the Italian Parliament Donat-Cattin was extradited from France in 1981.
Thanks to a special law which granted reduction of sentences for dissociates from terrorist organizations and for justice collaborators, Donat-Cattin obtained house arrest in October 1985 after having been acquitted (due to insufficient proofs) from the assassination of criminologist Alfredo Paolella. He was freed in May 1987.
He was struck and killed by a car on a highway near Verona in 1988.
- Giacchino, Claudio (22 June 1988). "Quante lacrime per Marco". La Stampa: 8.
- Montanelli, Indro; Mario Cervi (1993). L’Italia degli anni di Fango. Milan: Rizzoli.