Mario Pirani Coen (3 August 1925 – 18 April 2015) was an Italian journalist, economist, and writer.
Born in Rome, he became a member of the Association of Journalists of Lazio in January 1958. Politically closed to the Italian Communist Party, he left it after the Soviet invasion of Hungary in 1956. He later became an officer of Eni, the Italian state-owned oil company.
After the experiences with , Il Giorno and , he participated, together with Eugenio Scalfari, to the foundation of la Repubblica, a newspaper that became one of the first in Italy. He became the Deputy Director, with and . He was also editor of L'Europeo from 1979 to 1980, succeeding . In 1995 he won the Premiolino.
He died in Rome on 18 April 2015, aged 89.