Niccolò Tommaseo (Italian: [nikkoˈlɔ ttommaˈzɛːo]; 9 October 1802 – 1 May 1874) was a Dalmatian linguist, journalist and essayist, the editor of a Dizionario della Lingua Italiana in eight volumes (1861–74), of a dictionary of synonyms (1830) and other works. He is considered a precursor of the Italian irredentism.