Despite being little more than an improved M26, the M46 Patton was the first in a series of US medium tanks named after the legendary World War II general that became the mainstay of US armored forces during most of the Cold War. The main difference between the M26 and M46 was a new engine since the M26 was deemed underpowered by US authorities after the war. A bore evacuator and a single baffle muzzle break was also incorporated but otherwise the M46 remained nearly identical to its predecessor. Combat service was limited to the Korean War, where they proved superior to North Korean T-34/85s during the initial stages of the conflict and eventually became the main US tank in the peninsula once the M4s and M26s were withdrawn during 1951. Because of its relatively small production run (just over 1,000 examples), few M46s were exported; only a few were provided to Belgium, France and Italy before being equipped with the M47 which succeeded it in US and foreign service.

The M46 was developed from the M26E2 through the incorporation of a new Continental AV-1790 engine that gave it nearly twice the power of the M26 (and whose derivatives would be eventually used on most of the Patton tanks). An improved M46A1 had various mechanical and electrical improvements as well as newer engine and transmission. Some M46s were also equipped with M3 dozer kits.