The Panzerkampfwagen IV (Pz.Kpfw. IV), commonly known as the Panzer IV, is a German medium tank developed in the late 1930s and used extensively during the Second World War. Its ordnance inventory designation was Sd.Kfz. 161.
The Panzer IV was the most numerous German tank and the second-most numerous German fully tracked armoured fighting vehicle of the Second World War; 8,553 Panzer IVs of all versions were built during World War II, only exceeded by the StuG III assault gun with 10,086 vehicles. Its chassis was also used as the base for many other fighting vehicles, including the Sturmgeschütz IV assault gun, the Jagdpanzer IV self-propelled anti-tank gun, the Wirbelwind and Ostwind self-propelled anti-aircraft guns, and the Brummbär self-propelled gun.