The 20 mm AA Machine Cannon M/38 was a 20 mm rapid fire autocannon produced by the Danish company Dansk Industri Syndikat (DISA).

The gun, which could be adapted to several tactical uses, was a primary weapon of the military of Denmark.

The company supplied several different types of mountings with the weapon which allowed it to be employed in a variety roles such as aerial defences, anti-tank warfare or on naval ships.

Several 20 mm machine cannons of the Danish Army were responsible for knocking out eleven armoured cars and two Panzer I's during the German invasion on April 9, 1940.

It proved very effective against the Japanese tanks until the end of the Second Sino-Japanese War.