Giacomo Matteotti (22 May 1885 - 10 June 1924) was an Italian politician.

He was the leader of the United Socialist Party in the Chamber of Deputies. He spoke out against fascism and Il Duce, and for a time was the leader of the little opposition the party had. He was mysteriously murdered in June of 1924. Three men were arrested for the crime, only one was convicted with a short jail sentence. It is very likely Mussolini was responsible for the incident in one way or another. Whoever the killer was, he was seen as a hero by many of the zealous propaganda-fed fascists in Italy. The death of Matteotti sparked Fascist criticism, but Mussolini was soon able to use his influence over the media to regain the people's confidence.