The SK 105 is a light tank of Austrian origin. It was developed in the late 1960's to meet the requirements of the Austrian army. Subsequently it has been widely exported and production lasted some 30 years.

The SK 105 is based on the Austrian 4K 4FA armored personnel carrier. The driver is seated at the front, the commander and gunner in the turret and the engine and drive train is mounted at the rear. The turret oscilates, meaning that the upper part and gun mount pivot on the lower part. The turret is similar to the one used on the late production French AMX-13 light tank.

The main armament consists of the 105mm G1 rifled cannon. The gun is fed from two six round magazines allowing a rate of fire of 12 rounds per minute until the gun must be loaded by hand. The maximum range of the HEAT projectile is 2.7 km and APFSDS projectiles can penetrate a NATO single heavy target at 1.2 km. A 7.62mm MG74 machine gun is mounted as a coaxial weapon.

The steel armor provides protection against 20mm projectiles over the frontal arc. All around it protects from small arms fire and shell splinters. An NBC system is standard and six smoke grenade launchers are fitted.

The tracked chassis provides a good road speed and cross country mobility. A 320 hp turbocharged diesel provides propulsion. The SK 105 is not amphibious.

The SK 105 was acquired in quantity by Austria. Additionally it has been widely exported, mainly to South America and North Africa. It remains in widespread use today.