The Studebaker US6 (G630) was a series of 2+1⁄2-ton 6×6 and 5-ton 6×4 trucks manufactured by the Studebaker Corporation and REO Motor Car Company during World War II. The basic cargo version was designed to transport a 2+1⁄2-short-ton cargo load over any type of terrain in any weather. Most of these were exported to the Soviet Union under Lend-Lease by the US during World War II, since the competing GMC 6×6 CCKW design proved to be more suitable for Western Front conditions.

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.