The M4 Hybrid Sherman is a special combination of the first and second variants of the early-generation Medium Tank M4 (Sherman) family. The M4 Hybrid variant was built by Chrysler Corporation using an M4 variant main hull structure combined with an M4A1 variant frontal glacis, essentially a hybrid of cast and rolled armour. The U.S. Army did not adopt a new classification to distinguish them from the totally welded-hull M4 variant. Due to their striking resemblance, these were commonly misinterpreted as M4A1 variations in historical documents like unit rosters and even certain Ordnance Department Test Reports. The British designated them "Sherman I Hybrid." From August 1943 through January 1944, Chrysler produced 1676 units of M4 hybrids. Following the reconstruction of Italy in 1945, some M4 Hybrid variants were transported to Italy. In 1946, a minor military command was founded for territory defence, and the force was supplied with several M4 Sherman variants such as the M4 Hybrid, M4A4, M4A4 VC Firefly, and M4 Hybrid IC Firefly Tipo.

Introduced in Update "Starfighters", the M4 Hybrid is the first reliable foreign medium tank capable of engaging adversaries for the Italian ground forces. Multiple variants of the Medium Tank M4 (Sherman) family will serve as the backbone of the Italian ground forces. The M4 Hybrid is armed with a 75 mm M3 tank gun in a completely traversable turret that can fire a wide range of ammunition depending on the situation. The frontal cast hull construction of the M4 Hybrid variant, which results in a curved hull shape, is quite similar to that of the M4A1 variant. Nonetheless, its armour provides adequate protection against enemy fire from smaller calibre weapons, and it is a reliable medium tank capable of performing most duties on the battlefield.