The M35 2½-ton cargo truck is a long-lived 2½-ton 6x6 cargo truck initially used by the United States Army and subsequently utilized by many nations around the world. Over time it evolved into a family of specialized vehicles. It inherited the nickname "Deuce and a Half" from an older 2½-ton truck, the World War II GMC CCKW.

The M35 started as a 1949 REO Motor Car Company design for a 2½-ton 6x6 off-road truck. This original 6-wheel M34 version with a single wheel tandem was quickly superseded by the 10-wheel M35 design with a dual tandem. The basic M35 cargo truck is rated to carry 5,000 pounds (2,300 kg) off-road or 10,000 pounds (4,500 kg) on roads. Trucks in this weight class are considered medium duty by the military and the Department of Transportation.