The Sturmgeschütz III (StuG III) assault gun was one of Germany's most produced Armored fighting vehicle during World War II. It was built on the chassis of the Panzer III tank. Initially intended as a mobile, armoured light gun for infantry support, the StuG was continually modified until, by 1942, it was widely employed as a tank destroyer.

The Sturmgeschütz series is probably best known for its excellent price-to-performance ratio. By the end of the war, over 10,500 had been built.

The Sturmgeschütz III originated from an initial proposal that Colonel Erich von Manstein submitted to General Beck in 1935 in which he suggested that Sturmartillerie (Assault Artillery) units should be used in a direct-fire support role for infantry divisions. To that end, on June 15, 1936, Daimler-Benz AG received an order to develop an armoured infantry support vehicle capable of mounting a 75 mm (2.95 in) artillery piece. The gun was to have a limited traverse of a minimum of 25 degrees and be mounted in a fully enclosed superstructure that provided overhead protection for the crew. The height of the vehicle was not to exceed that of the average man.

Daimler-Benz AG used the chassis and running gear of its recently designed Panzerkampfwagen III medium tank as a basis for the new vehicle. Prototype manufacture was passed over to Alkett, which produced five examples in 1937 of the experimental 0-series StuG based upon the PzKpfw III Ausf. B. These prototypes featured a mild steel superstructure and Krupp’s short-barreled 75 mm Sturmkanone 37 L/24.

As the StuG III was intended to fill an anti-infantry close support combat role, early models were fitted with a low-velocity 75 mm StuK 37 L/24 gun, firing high explosive shells. After the Germans encountered the Soviet T-34, the StuG III were armed with the high-velocity 75 mm StuK 40 L/43 (Spring 1942) or 75 mm L/48 (Autumn 1942) anti-tank gun.

Later models of the StuG III had a 7.92mm MG34 mounted on the hull for added anti-infantry protection.

In 1944 the Finnish army received 59 StuG III from Germany and used them against Soviet Union. These Stug III's destroyed at least 87 enemy tanks, for a loss of only 8 StuG's (some of these were destroyed by the crew before they abandonded the vehicle). After the war most of surviving vehicles were used as main battle tanks of the Finnish army.

After the Second World War, the Soviet Union gave some of the captured German vehicles to Syria, which continued to use them at least until the Six Days War (1967).

StuG III Ausf. G (Sd.Kfz 142/1; 1942-45, 7,893 produced)
The final, and by far the most common, of the StuG series. The G-series StuG used the hull of the Panzer III Ausf. M and, after 1944, a second machine gun. Later versions were fitted with the Saukopf (Ger. pig's head) gun mantlet, which was more effective than the original box metal structure at deflecting shots.