The M35 2 1⁄2-ton cargo truck is a long-lived 2 ½-ton 6×6 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 2 1⁄2-ton truck, the World War II GMC CCKW.
 
The versatility of the pattern was perhaps shown best in its usage as an armored "gun truck" for patrol duties and convoy escort. The first conversions of the pattern were performed by the U.S. military in Vietnam. U.S. Army Artillery Battalions (Automatic Weapons, Self-Propelled) were often assigned Artillery Batteries (.50-caliber), units equipped with M35 trucks and M55 Quadmount systems mounting four M2 Browning machine guns.