31st Division may refer to:

• 31st Division (German Empire), a unit of the Imperial German Army
• 31st SS Volunteer Grenadier Division, a unit of the German Army
• 31st Division (Imperial Japanese Army), a unit of the Imperial Japanese Army
• 31 Infantry Division Calabria, a unit of the Italian Army
• 31st Division (United Kingdom), a unit of the United Kingdom Army
• 31st Infantry Division (Russian Empire), a unit of the Russian Empire
• 21st Guards Motor Rifle Division (31st Guards Rifle Division), a unit of the Soviet Army
• 31st Infantry Division (United States), a unit of the United States Army

Armoured divisions

• 31st Indian Armoured Division, a unit of British India during World War II
• 31st Armored Division (Israel), a reservist armored division in Israel that fought in the Six-Day War
• 31st Tank Division (Soviet Union), a unit of the Soviet Army

Aviation divisions

• 31st Air Division, a unit of the United States Air Force

• 31st Group (disambiguation)
• 31st Brigade (disambiguation)
• 31st Regiment (disambiguation)
• 31st Battalion (disambiguation)
• 31st Squadron (disambiguation)

This disambiguation page lists articles about military units and formations which are associated with the same title.
If an internal link referred you to this page, you may wish to change the link to point directly to the intended article.