Mario Fiorentini (7 November 1918 – 9 August 2022) was an Italian partisan, spy, mathematician, and academic, for years a professor of geometry at the University of Ferrara.

[8] On 9 September 1943, Fiorentini took part in the battle against the Germans at Porta San Paolo among the ranks of the members of the Action Party; in October he organized and placed himself in command of the central Patriotic Action Groups (GAP), in the IV operational area "Roma centro", taking the battle name of "John"; this formation, together with the GAP Carlo Pisacane, belonged to the partisan structure belonging to the network commanded by Carlo Salinari.

[11] On 18 November, Fiorentini was responsible for covering some of the Pisacane gappists who entered the Teatro Adriano, having learned that the following day General Stahel, commander of the square in Rome, would be present among high-ranking German officers and republican fascist authorities (including the marshal Rodolfo Graziani).

[12] On the evening of 17 December 1943, with Lucia Ottobrini, Carla Capponi and Rosario Bentivegna, Fiorentini took part in an action against a German officer with a bag full of documents.

[14][15] On 26 December, while a group composed of Ottobrini, Capponi, Bentivegna and Di Lernia was covering the action, Fiorentini threw an explosive package containing two kilograms of TNT while bicycling past the entrance of Regina Coeli prison, at the moment when 28 German soldiers were changing the guard, causing 5 deaths and about 20 wounded; another 2 would soon be dead.

[18] On 10 March 1944, Fiorentini, with Ottobrini, Bentivegna and Franco Ferri, coming out from behind the kiosks of the market in Piazza Monte d'Oro, threw bombs at a procession of fascists in via Tomacelli, causing three deaths and numerous injuries.

[19] It was Fiorentini who noticed, from his hiding place near via del Tritone, the daily passage of the South Tyrolean policemen of the SS Police Regiment Bozen.

After the liberation of Rome, starting from July 1944, Fiorentini was placed in command of the "Dingo" mission, under the American Office of Strategic Services (OSS), and continued the resistance in Northern Italy (Emilia and Liguria).

[26] In 2013, a documentary was made, called L'uomo dai quattro nomi (The Man With The Four Names),[a] directed by Claudio Costa, in which Fiorentini tells his story in the Resistance.

[29] Celebrations were held in the Federico Di Donato primary school in Rome in the Esquilino district on 13 November 2018 in which a new book written in collaboration with Ennio Peres [it] was presented to Fiorentini.