The Valentine XI was a British infantry tank. Its development started as a private venture of Vickers-Armstrong in 1938, based on experience with the A9, A10 and A11 cruiser and infantry tank designs. The War Office initially wasn't satisfied with only a two-man turret: a three-man turret was fitted so the commander would not become overwhelmed with tasks during battle. With the situation in Europe worsening, the design was approved in April 1939 and first deliveries were made in May 1940. The Valentine XI was an upgunned version of the earlier X, featuring an Ordnance QF 75 mm gun and 210 hp GMC 6004 diesel engine; the armour was also welded rather than riveted. Nearly all variants of the Valentine tank except Mk I were sent to USSR as part of the Lend-Lease act.

The Valentine was introduced along with the initial British tree line in Update 1.55 "Royal Armour". Featuring a deadly 75 mm gun paired with quite fast reload and excellent armour protection, the Valentine XI is a formidable opponent. While angled, the majority of its opponents will struggle to penetrate its hull armour. The turret, although more vulnerable, can also deflect a few rounds due to its shape. The main drawback of the Valentine is its very slow turret rotation speed, only 2.4 km/h reverse speed and low maximum speed of only 24 km/h, making the Valentine slower than even the Maus.