The M35 2½-ton cargo truck is a long-lived 2½-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 2½-ton truck, the World War II GMC CCKW.

The 2+1⁄2-ton, 6×6 truck was a standard class of medium duty trucks, designed at the beginning of World War II for the US Armed Forces, in service for over half a century, from 1940 into the 1990s. Also frequently known as the deuce and a half, or just deuce, this nickname was popularized post WWII, most likely in the Vietnam war era. The basic cargo versions were designed to transport a cargo load of nominally 2+1⁄2 short tons over all terrain, in all weather. The 2+1⁄2-ton trucks were used ubiquitously in World War II, and continued to be the U.S. standard medium duty truck class after the war, including wide usage in the Korean and Vietnam Wars, as well as the first Gulf War.