The Panzerkampfwagen III Ausführung M (Panzer III M) (Sd.Kfz. Index: Sd.Kfz. 141/1) is the eleventh variant of the Panzerkampfwagen III medium tank family (the "I" variant was skipped). In February 1942, orders for the Panzer III M were placed. They shared the same characteristics as the Panzer III L but were outfitted with deep-wading equipment. It was mounted with the same long-barrelled 50 mm Kampfwagenkanone (KwK) 39 L/60 tank gun. While the greater length of the barrel increased the 50 mm KwK 39 L/60 tank gun's velocity and penetration power over the previous 50 mm KwK38 L/42 tank gun, the introduction of the Soviet T-34 medium tanks and KV-1 heavy tanks quickly rendered it obsolete. With the arrival of the long-barrelled 75 mm KwK40 L/43 tank gun in the Panzer IV F2, the German Wehrmacht eventually decided to discontinue all future Panzer III manufacturing and redirect all resources to the development of more Panzer IVs. Beginning in May 1943, 5 mm side skirt armour panels known as Schürzen were installed on the hull side to prevent the Soviet 14.5 mm anti-tank rifle from penetrating the Panzer III's side armour. More plates were added to completely surround the turret, leaving only the front open for the main gun. Since the Panzer III M fought in the North African Campaign during fierce engagements with British forces, it has been painted in the distinctive Dunkelgelb yellow coat.

Introduced in the Closed Beta Test for Ground Forces before Update 1.41, the Panzer III M variant retains the overall characteristics of the earlier Panzer III L variant. The most visible changes are the integration of 5 mm Schürzen armour plates on both sides of the hull, as well as additional armour plates that completely surround the turret, leaving only the front open for the main gun. This layout is quite similar to the Panzer IV H variant of the Panzer IV medium tank family. It is the ultimate modification of the Panzer III medium tank, combining firepower, protection, and mobility. The enhanced protection will undoubtedly be appreciated by players, particularly against low-calibre tank guns from early opponent light tanks. However, when fighting against enemies of higher rank, the Panzer III M will suffer greatly, owing to the fact that the 50 mm KwK39 L/60 tank gun lacks the penetration required to engage enemies from a distance. Closing in on the adversary is frequently essential, yet doing so often allows the enemy to penetrate the Panzer III M more easily.