A sandrail, or sand rail, is a lightweight motor vehicle specifically built for travelling across sandy terrain. Its light weight and high flotation tires allows the sandrail to skim over the top of the sand without getting stuck. A sandrail has a low center of gravity which permits it to turn even on the face of a sand dune. Many types of off-road vehicles are relatively top heavy and can only safely climb or descend steep hills with a mostly perpendicular approach.

It is built from a tubular space frame chassis that incorporates an integrated roll cage. There are usually no windows, doors, fenders, or body panels. The engine is typically at the rear or mid mounted. Lightweight and air cooled engines like from the VW Beetle or the Chevrolet Corvair were originally used, but water cooled engines are also seen.

The front tires are normally narrow as this allows them to dig into the sand while turning, and the rear tires are large (to provide traction). Sandrails are almost always rear-wheel drive. Ideally, the rear tires will be paddle tires.

Most people start out with VW Baja Bugs and move up to the sandrails.