The M113, one of the earliest and most common APCs, on duty during the Vietnam War

Armoured personnel carriers (APCs) are light armoured fighting vehicles for the transport of infantry. They usually have only a machine gun although variants carry recoilless rifles, anti-tank guided missiles (ATGMs), or mortars. They are not really designed to take part in a direct-fire battle, but to carry the troops to the battlefield safe from shrapnel and ambush. They may have wheels or tracks. Examples include the American M-113 (tracked), the French VAB (wheeled) and the Soviet BTR (wheeled) or BMP-1 series's.

Most armoured personnel carriers use a diesel engine comparable to that used in a large truck or in a typical city bus. The M-113 for instance used the same engine as the standard General Motors urban bus. A single M-113 moving at top speed generates as much noise as a General Motors urban bus moving at top speed. However, the typical armoured personnel carrier contains only six or ten soldiers while a typical urban bus can carry thirty to fifty seated passengers, and hundreds when standing passengers are included.

Because of the increase usage of APCs in urban warfare, extra armor was added to some types of APCs. In some cases, old tanks were converted to heavy APCs, giving infantry the protection of the much more heavily-built tank. The best example for such an HAPC is the heavy IDF Achzarit, which is considered one of the best-protected APCs in the world. Interestingly, the original APC was created in World War II, when Allied leaders found a better use for a poorly armed tank, the Canadian Ram, whose turret they took off to create the Kangaroo.

Another result of urban warfare is the spreading of wheeled APCs, such as the American Stryker or the German Fuchs . The Strykers are very versatile and they come with several configurations: APCs, CEV, 105mm gun, mortar, anti-tank gun, recon, communication etc.

Romanian Transportor Auto Blindat APCs that made infamous frontline news in 1989 were mostly 8-wheel, massive Romanian clones of the Soviet BTR60 APC. Soldiers hated this machine, with uncomfortable access from above and heavy latches that seemed designed to snap one's fingers off. Limited visibility and clumsy maneuverability in an urban environment might have contributed (along with bad will, of course) to the numbers of deaths through crushing during the Romanian Revolution.

In WWI some of the tanks of the period were also converted to carry supplies and infantry. The Mark V* tank was designed with a extra section for a squad of infantry to be carried, becoming the first purpose designed tracked APC. The first specialised APC was the Mark IX of 1918.