[1] Born to a working-class family in Tresigallo, a small town in the Province of Ferrara, Rossoni was imprisoned in 1908 for his revolutionary activities as a syndicalist.

Along with Alfredo Rocco and Giuseppe Bottai, Rossoni is considered to have played a large role in the development of Italy's Fascist State.

[6] Regarded as one of the founders of “Fascist syndicalism”,[7] Rossoni had learned in the United States to distrust both the capitalists and various orthodox socialist movements that urged internationalism, recalling his conversion to social nationalism at the first congress of Fascist unions in June 1922: "We have seen our workers exploited and held in low regard not only by the capitalists but also by the revolutionary comrades of other countries.

"[8]One of Rossoni's first syndicalist ventures in Italy was helping to found the Unione Italiana del Lavoro (UIL) in June 1918.

"[22] For Rossoni, fascism was nothing less than "The great revolution of the twentieth Century: a revolution which in its subsequent development will be nourished by the immortal spirit of the Italian people,…” [23] To display their solidarity for workers, Rossoni and Roberto Farinacci initially supported the metallurgical workers' strikes in Brescia in March 1925 in an attempt to get higher wages and union recognition.

[32] Rossoni made himself famous on July 25, 1943, by voting against Mussolini's leadership inside the Grand Council (thus siding with the coup d'état initiated by Dino Grandi).

When Mussolini regained power in northern Italy, creating the Italian Social Republic, Rossoni was sentenced to death in absentia.