The BTR-40 was the USSR's first mass produced APC and which served as the basis for other combat vehicles. The BTR-40 was based on the lengthened chassis of the GAZ-63 4x4 truck with a redesigned, armored frame made of all-welded steel. It still retains the look and configuration of a standard truck, with the entine at the front, driver and commander seated in the center, and the crew compartment at the rear. This can fit up to eight fully loaded infantrymen who enter and exit through twin rear doors. The crew compartment has an open top but carries a tarpaulin cover if needed, and is equipped with three pintle mounts for machine guns although only one is typically carried on the front-most pintle; later versions also add firing ports at the sides of the hull and the rear. The BTR-40 was a relatively simple design that lacked NBC protection (intially) or amphibious capability, the latter which would eventually be added in the BDRM-1 amphibious scout car which was based on it. Despite these limitations, it would go on to service with a large number of Warsaw Pact allies and Soviet client states, primarily in Africa and Asia including China which produced its own copy. The BTR-40 was eventually replaced by the BTR-152 and later the BTR-60 which was a much more modern and revolutionary APC design.

Development of a new APC was led by V. K. Rubtsov and resulted in the prototype BTR-141 in 1947 which entered production in 1950 as the BTR-40 and the BTR-40A SPAAG variant armed with twin 14.5-mm KPV machine guns. The addition of a tire pressure regulation system resulted in the BTR-40V and the open top was replaced by an armored roof in the BTR-40B which was optimized as a scout car. It lso added NBC protection and provision for heavier machine guns of up to 14.5-mm caliber. Non-combat vehicles include the BTR-40Kh chemical reconnaissance vehicle and the BTR-40ZhD rail scout car which could operate on railway lines. An amphibious scout car version was initially known as the BTR-40P but later redesignated BRDM-1 and is described separately. Foreign versions were known as the SPW-40 in East Germany, Type 55 in China, and the Walid in Egypt.