Roberto Cessi (20 August 1885 – 19 January 1969)[1] was an Italian historian and politician, specializing in Venetian history.

After the Second World War he was elected deputy of the PSI in the first legislature: from 1 June 1948 to 1951 he presented six bills; he actively collaborated with the Encyclopedia Treccani, was a member of the Accademia dei Lincei and president of the Venetian Deputation of Homeland History (Deputazione di Storia Patria per le Venezie).

He studied and published volumes dedicated above all to the history of Venice and the Veneto, from the Middle Ages to the Risorgimento.

Between 1944 and 1946 he published his Storia della Repubblica di Venezia ("History of the Republic of Venice") in two volumes.

He also devoted himself to other topics: at the request of Delio Cantimori, in 1954 he published a biography of Martin Luther.