40th Division or 40th Infantry Division may refer to:
Infantry divisions 40th Division (German Empire), Imperial German Army 40th Infantry Division "Cacciatori d'Africa", Italian division of World War II 40th Division (Imperial Japanese Army) 40th Infantry Division (Russian Empire) 40th Guards Rifle Division, Soviet Union 40th Rifle Division, Soviet Union 40th Division (Syria) 40th Division (United Kingdom) 40th Infantry Division (United States) 40th Division (Yugoslav Partisans) 40th Infantry Division Slavonska, Yugoslav Army
Armoured divisions 40th Armored Division, United States
Artillery divisions 40th Anti-Aircraft Artillery Division, Soviet Union
Aviation divisions 40th Air Division, United States Air Force
See also List of military divisions by number 40th Brigade (disambiguation) 40th Regiment (disambiguation) 40th Battalion (disambiguation) 40th Squadron (disambiguation)