The Alfa Romeo 800 is a heavy truck produced by Alfa Romeo between 1940 to 1947. It was first produced as a military version 800RE and after the war as civilian version. The military version was initially used only in the Italian Army ("Regio Esercito"), mainly in North Africa, Russia and occupied France. The 800 was equipped with 8.7 L diesel engine with fuel injection, it could reach top speed of 50 kilometres per hour (31.1 mph). There were also gas generator and a gasoline models produced. A half track prototype version a CSEM 800RE (Centro Studi ed Esperienze della Motorizzazione - the Italian Army's vehicle research and development organization) was also made for Italian army.

The 800 was replaced by the model 900.