Six wheeled ATVs were the original ATVs, though they currently do not fall under the legal classification of an ATV. They were made in the United States in the 1960s by multiple manufacturers, and were able to travel on land or in water by using the wheels or an optional out-board motor for propulsion.

The riders rode inside the vehicle in seats and steered with a wheel or a stick. They featured six (or sometimes 8) wheels which were typically all driven. The only suspension was from the huge balloon tires that ran less than 5psi. They are slower but much more precision than their 3 and 4 wheeled counter-parts, and they can swim.

The current legal classification of an ATV states that it is steered by handle bars, like a motorcycle or bicycle, so the six-wheeled variety is not legally an ATV. It is often known as an AATV, or Amphibious All-Terrain Vehicle.