The BA-64 (БА-64, from Russian: Бронированный Автомобиль, Bronirovaniy Avtomobil, literally "armoured car") was a Soviet four-wheeled armoured scout car. Built on the chassis of a GAZ-64 or GAZ-67 jeep, it incorporated a hull loosely modeled after that of the Sd.Kfz. 221. The BA-64 was developed between July and November 1941 to replace the BA-20 then in service with armoured car units of the Red Army. Cheap and exceptionally reliable, it would later become the most common Soviet wheeled armoured fighting vehicle to enter service during World War II, with over 9,000 being manufactured before production ended.

The BA-64 represented an important watershed in Soviet armoured car technology, as its multi-faceted hull gave its crew superior protection from small arms fire and shell fragments than the BA-20. BA-64s also possessed a much higher power-to-weight ratio and the placement of their wheels at the extreme corners of the chassis resulted in exceptional manoeuvrability. Following the adoption of the BTR-40, the Soviet government retired its remaining fleet of BA-64s and exported them as military aid to various nations. In East German service, they served as the basis for the later Garant 30k SK-1. North Korean BA-64s saw action against the United Nations Command during the Korean War.

During the 1930s, the Soviet Union devoted much effort and funding to the development of six-wheeled medium or heavy armoured cars. A primary shortcoming of these vehicles was their lack of all-wheel drive, however, which restricted them to roads. In 1940, the Main Directorate of Soviet Armoured Forces (GABTU), issued a requirement for new armoured car designs which could operate effectively on open terrain and possessed an all-wheel drive chassis. This ushered in the development of several new 4X4 designs, such as the LB-62 and the BA-NATTI. Although these were the first all-wheel drive Soviet armoured cars, neither was accepted for service with the Red Army, as they suffered from excessive weight, fuel consumption, and poor operating range.

During Operation Barbarossa, Nazi Germany's rapid offensives in Ukraine and western Russia temporarily disrupted new military projects as most Soviet factories involved with the production of armoured fighting vehicles were forced to evacuate their facilities and relocate operations east of the Ural Mountains. Gorkovsky Avtomobilny Zavod (GAZ) was one of a few exceptions to the rule, as it was already located east of Moscow. Its contribution to the early Soviet war effort was strategically vital, since it could continue manufacturing vehicles to replace the massive losses then being sustained by the Red Army while the rest of the local defence industry was struggling to relocate and reorganise. GAZ increased its manufacture and assembly of light tanks accordingly, as well as continuing to produce military trucks. Since the programme to mass produce a new all-wheel drive armoured car had been interrupted by the German invasion, it also fell to GAZ to investigate possibilities in that regard.

GAZ technicians initiated concept work on a new armoured car designated Izdeliye 64-125 on July 17, 1941, basing its construction and design on a preexisting light vehicle chassis. This was to ensure the manufacturing process could in be undertaken in an economical and rapid manner. After some deliberation, the GAZ-64 jeep was chosen as the base for the Izdeliye 64-125. This chassis was considered ideal due to its short wheel base and excellent ground clearance, and the fact that its mechanical parts were already in serial production. The original Izdeliye 64-125 bore almost no similarities with what would later become the BA-64; it resembled little more than a shorter BA-20.

On August 23, a captured German Sd.Kfz. 221 scout car was exhibited near Moscow by the Red Army. Vitaliy Grachev and other GAZ engineers were permitted to inspect the vehicle; a month later Grachev arranged to have it brought to the GAZ factory for a detailed analysis. Grachev was impressed by the highly faceted armour plate on the Sd.Kfz. 221, which was angled for maximum ricochet, and he ordered that a similar hull be incorporated into the Izdeliye 64-125. In late November, GAZ assembled the first three prototypes carrying the new hull. Field trials with the Red Army commenced on January 9, 1942. The Izdeliye 64-125 was accepted for service as the BA-64 on March 14, 1942.

The BA-64 was initially armed with a single 7.62mm Degtyaryov machine gun in an open-topped turret. The machine gun was mounted on a fixed mount that allowed it to be elevated sufficiently to engage low-flying aircraft. BA-64s started being issued in large numbers to Soviet units in early 1943. Around the same time a specialist driving school was set up to train BA-64 drivers. For reasons still unclear, only fifty armoured cars of this type were manufactured in 1942 and mass production was not undertaken until the first six months of 1943, when over a thousand were manufactured. Even after 1943, production figures remained inconsistent and could fluctuate greatly from year to year. In June 1943, the GAZ workshops that produced the BA-64 were heavily damaged or destroyed by German air raids, and production ceased altogether until the plant could be restored. A few technical shortcomings of the GAZ-64 chassis had to be resolved in that time.

BA-64s remained unique in that they were the only new Soviet armoured car design to be produced during World War II. They had better armour, speed, range, and off-road capability than any other wheeled fighting vehicles in Soviet service, although due to the limitations of the chassis they could only carry a single light machine gun. Unlike the BA-3/6 and BA-20 heavy armoured cars, which were armed with anti-tank cannon, the BA-64 was not considered suitable for front-line combat against German armour. It was, however, widely used for transporting officers, liaison purposes, reconnaissance, and other secondary battlefield tasks.