The BTR-70 is an eight-wheeled armored personnel carrier (Russian: бронетранспортёр, БТР, romanized: bronetransportyor, lit. 'armored carrier') originally developed by the Soviet Union during the late 1960s under the manufacturing code GAZ-4905. On August 21, 1972, it was accepted into Soviet service and would later be widely exported. Large quantities were also produced under license in Romania as the TAB-77.
 The BTR-70 was developed as a potential successor for the earlier BTR-60 series of Soviet wheeled armored personnel carriers, specifically the BTR-60PB, which it most closely resembled. It evolved out of an earlier, unsuccessful project known as the GAZ-50 to design a new wheeled infantry fighting vehicle on the chassis and drive train of a BTR-60PB. It initially received the NATO reporting name BTR M1970.
 In 1971, the Soviet Armed Forces began investigating the possibility of an updated BTR-60PB redesigned to make the vehicle more compatible with the BMP-1 in terms of tactical training. This resulted in the development of a BTR-60PB prototype essentially converted into a wheeled infantry fighting vehicle, designated Obiekt 50 or GAZ-50. Despite retaining the original BTR-60PB chassis, the GAZ-50 incorporated several elements of the BMP's design, including similar seating arrangements in the passenger compartment. The revised internal layout reduced the number of passengers to nine. New hatches were also provided for debarking in the lower hull, between the second and third wheel stations. Other modifications included a slightly thicker hull, increased power-to-weight ratio, and additional firing ports. Another feature retained from the BTR-60 was the twin-engine arrangement, although in the GAZ-50 torque produced by the right engine powered the first and third wheel stations, while the left engine powered the second and fourth. This alteration was to allow the vehicle to continue moving even if one engine failed. The prototype was armed with a turret resembling that of the BMP-1, incorporating the same 73mm 2A28 Grom low-pressure smoothbore cannon.
 There was some debate as to the GAZ-50's viability in its intended role; for example, projected manufacturing costs were high due to the incorporation of the BMP-1 turret and armament. Furthermore, while the prototype would allow motorized units to emulate the tactics of Soviet mechanized infantry, it simply did not offer the same protection, mobility, and firepower of the BMP. Most of the funding earmarked for the program was thus diverted into producing larger numbers of BMPs instead, as well as ensuring their wider introduction beyond Soviet tank divisions. A second GAZ-50 prototype was built, designated Obiekt 60 mounting a 14.5mm machine gun in exactly the same turret as that carried by the BTR-60 series; this was accepted as a generic replacement for the BTR-60PB in motorized rifle regiments. In Soviet service, the new BTRs received the designation BTR-70.
 Compared to the earlier BTR-60PB, relatively small numbers of BTR-70s were produced. The design was still regarded as suffering from some of the same disadvantages, such as the two flammable petrol engines and the poor means of entry and exit. These flaws became especially evident when the vehicle was tested in combat during the Soviet–Afghan War. As a result, in 1984 the Soviet Army took delivery of a new wheeled armored personnel carrier, the BTR-80, which was powered by a single 260 horsepower diesel engine and a simpler drive train. Production of the BTR-70 was terminated that year.
 The Soviet Union only exported BTR-70s to four other states: Afghanistan, the German Democratic Republic (East Germany), Hungary, and Romania, which also purchased a license to manufacture the design locally. However, many have since been inherited by the armies of various post-Soviet republics or re-exported.
 The BTR-70 is powered by two petrol engines. Early production vehicles used 115 hp GAZ-69B 6-cylinder engines, but most vehicles have now been retrofitted with the more powerful ZMZ-49-05 V-8 engines. The vehicle is fully amphibious, propelled when afloat by a single water jet mounted at the rear of the hull. To prepare the vehicle for water, the driver erects a trim vane and switches on the bilge pumps from within the vehicle.
 The standard equipment includes a central tire-pressure regulation system that allows the driver to adjust the tire-pressure to suit the terrain being crossed. Also fitted is an R-123M radio set and an R-124 intercom. The driver's optical equipment consists of three TNPO-115 vision blocks and a TNP-B day vision device, which can be replaced by a TVNO-2B night vision device. The commander also has three TNPO-115s and either a TPKU-2B day sight or a TKN-1S night sight accompanied by an OU-3GA-2 infra-red search light. The turret is fitted with a PP-61AM (or 1PZ-2) periscopic sight for the gunner and the infantry group in the troop compartment is provided with TNP-B devices. The BTR-70 also has an FVU NBC filter system and a DK-3B detection device.
 The armaments consist of a KPVT heavy machine gun with 500 rounds and a coaxial 7.62 mm PKT machine gun with 2,000 rounds. Also on board are two "Igla" or "Strela-3" MANPADS, and optionally two AGS-17 grenade launchers at the expense of two infantry men.
 The BTR-70 first saw service during the Soviet–Afghan War. A very small quantity of BTR-70s were donated or sold to the People's Armed Forces for the Liberation of Angola in the mid-1980s by an undisclosed country; these saw action during the Angolan Civil War. BTR-70s were deployed by the United Nations Protection Force (UNPROFOR) in Bosnia-Herzegovina during the Yugoslav Wars.
 BTR-70s of the Armed Forces of Ukraine have been deployed in the War in Donbass, with some being captured by pro-Russian militias of the Donetsk People's Republic.
 During 2021 Kyrgyzstan–Tajikistan clashes BTR-70s were deployed by Kyrgyzstan with at least one BTR-70M lost to enemy fire.
 During the 2022 Russian invasion of Ukraine, BTR-70s were deployed by Russia with four BTR-70s lost (three destroyed, one captured) and three BTR-70M (two destroyed, one captured) visually confirmed by Oryx  as of 4 September 2023.