The Guy Quad Ant was a four-wheel drive version of the Guy Ant and was launched in 1938.
The Quad Ant was initially introduced as a field artillery tractor. The first two prototypes, one with a petrol engine and one with a Gardner diesel engine, were produced under a contract placed in December 1937. The fist major contract calling for 444 vehicles was placed in November 1938 with deliveries starting in late August the year after.
Most of the production vehicles had the beetle-neck body style that it shared with the Morris-Commercial C8. The Quad Ant had a 3686cc four-cylinder Meadows 4ELA liquid cooled engine, fitted with a single carburettor. The engine produced 60bhp and the Quad Ant was fitted with a four-speed gearbox.
In 1943 the GS version was introduced. Besides cargo this version was used as tractor for a six-pounder anti-tank gun. When production ceased in 1944 around 4.000 had been made.
As a part of an attempt to rationalise the post-war fleet on the British Army the Ant and Quad-Ant was declared obsolete and auctioned of or passed on to other countries.
An armoured scout-car, based on the Quad-Ant Field Artillery Tractor, was designed by the Woolwich Arsenal.