81st Division or 81st Infantry Division may refer to:
Infantry divisions 81st Podrinje Independent Division, Republic of Bosnia and Herzegovina 81st Division (People's Republic of China) 81st Infantry Division (Wehrmacht), Germany 81st Reserve Division, German Empire 81st Division (Imperial Japanese Army) 81st Division (Nigeria) 81st Division (Philippines) 81st Infantry Division (Russian Empire) 81st Guards Rifle Division, Soviet Union, later the 81st Guards Motor Rifle Division 81st Rifle Division, Soviet Union 81st (West Africa) Division, United Kingdom 81st Infantry Division (United States)
Cavalry divisions 81st Cavalry Division, Soviet Union
See also List of military divisions by number 81st Brigade (disambiguation) 81st Regiment (disambiguation) 81st Squadron (disambiguation)