The Messerschmitt Me 323 Gigant ("Giant") was a German military transport aircraft of World War II. It was a powered variant of the Me 321 military glider and was the largest land-based transport aircraft of the war. A total of 213 are recorded as having been made, a few being converted from the Me 321. The Me 323 was the result of a 1940 German requirement for a large assault glider in preparation for Operation Sea Lion, the projected invasion of Great Britain. The DFS 230 light glider had already proven its worth in the Battle of Fort Eben-Emael in Belgium (the first ever assault by gliderborne troops), and would later be used successfully in the invasion of Crete in 1941.

The requirement for a heavy air transport capability still existed, with the focus now on the forthcoming Operation Barbarossa, the invasion of the Soviet Union.