Autoloader (also called automatic loader) is a mechanical system to load the main armament and so eliminate one member (human loader) from the fighting vehicle's crew.

There are two main types of autoloader, the bustle and the carousel.

In the bustle autoloader, the rounds are stowed in tubes on an endless belt within the autoloader. A microprocessor is used to recognise various types of ammunition.

In the carousel autoloader, the rounds are stowed in a circular, rotating structure on the turret floor. Ammunition is two-piece, the projectile and charge are stowed one above the other, each complete round called a cassette. Another version – the projectile and charge are positioned at an angle of 90 degrees to each other in a foldable loading tray, the projectile being placed horizontally, and the charge, vertically. As in the bustle autoloader, a microprocessor is used to recognise various types of ammunition.

The first tank autoloader was used in the Soviet-designed T-64 main battle tank (MBT). Nowadays, the most modern tanks fitted with an autoloader include French Leclerc, Japanese Type 90, Ukrainian Yatagan MBTs (bustle autoloader) as well as Russian T-90S, Chinese Type 98, Ukrainian T-84 MBTs (carousel autoloader).

Some Western nations have developed prototype autoloaders for their future tanks with larger calibre guns, as, for example, did Germany for its 140mm-armed Leopard MBT.