The Tank, Cruiser Mark VIB, Crusader III (A15) is the third variant of the A15 Crusader cruiser tank family. Due to design delays with the British Army's seventh cruiser tank, the Cavalier (A24), the Crusader III was the first British tank to be equipped with the 57 mm Ordnance QF 6-pounder tank gun. An extractor fan was also installed in the turret to remove fumes produced by the tank gun's fire. The tank crew was reduced to three as the larger tank gun limited turret space. To make room for ammunition storage, the auxiliary turret was removed. The Crusader III was also equipped with the Mark IV Liberty engine, which solved many of the earlier reliability difficulties. Production began in May 1942, with 144 units completed by July. The Crusader III first saw service in October 1942, with approximately 100 units taking part in the Second Battle of El Alamein.

Introduced in Update 1.55 "Royal Armour", the Crusader III boasts significant improvements in firepower over the Crusader II. Despite being categorized as a light tank, the Crusader III is only light due to its light armour. The 57 mm Ordnance QF 6-pounder outperforms the previous 40 mm Ordnance QF 2-pounder mounted on the Crusader II. This translates to enough firepower to engage most tanks from the front. Furthermore, as a result of its low profile, players can easily hide behind vegetation and obstacles such as walls, shooting from a concealed position or retreating under smoke if the situation becomes too dangerous. Overall, this tank suits the playstyle of a frontline support tank; moreover, players can act as flankers and either neutralize threats or scout for enemy tanks for allies.