The Leopard A1A1 (L/44) is an experimental version of the Leopard A1A1 tank equipped with a 120mm Rheinmetall L/44 smoothbore gun. Rheinmetall developed the Leopard 1 with a 120 mm gun as a private venture as the company's management hoped to attract numerous potential customers. They believed the German Army might be interested in a more powerful gun that would partially unify with the newest Leopard 2. Foreign customers could be attracted by upgrading some characteristics of the older tank to the level of modern MBTs. Thus, in the early 1980s, several Leopard A1A1 tanks were retrofitted with the new gun. The gun mantlet was modified, and the ammunition rack mounts were adapted to store the larger rounds. Soon afterward, in 1985, the tanks received the EMES 18 fire control system from the Leopard 1A5. These improvements significantly increased the price but failed to substantially increase combat effectiveness, which is why this version of the Leopard ultimately found no customers.

The Leopard A1A1 (L/44) was introduced in Update 1.81 "The Valkyries". From a distance, it can easily be confused with the standard Leopard A1A1, but this variant has a new, high-penetration, 120-mm gun that allows it to effectively engage all potential opponents. Additionally, it has a laser rangefinder and a thermal sight for the gunner, turning the tank into a true "hunter," especially considering its excellent mobility. However, it has weak armor that does not protect against the automatic cannons of many IFVs and SPAAs.