Pietro Sandro Nenni (Italian pronunciation: ['pj??tro 'n?nni]; 9 February 1891 – 1 January 1980) was an Italian socialist politician, the national secretary of the Italian Socialist Party (PSI) and lifetime Senator since 1970.
He was a recipient of the Stalin Peace Prize in 1951.
He was a central figure of the Italian left from the 1920s to the 1960s.