56th Regiment
- 56th (King's Own) Anti-Tank Regiment, Royal Artillery
- 56th (West Essex) Regiment of Foot
- 56th Air Defense Artillery Regiment
- 56th Brigade (disambiguation)
- 56th Division (disambiguation)
- 56th Field Artillery Regiment, RCA
- 56th Group (disambiguation)
- 56th Guards Air Assault Regiment
- 56th Illinois Volunteer Infantry Regiment
- 56th Infantry Regiment (United States)
- 56th Massachusetts Infantry Regiment
- 56th New York Volunteer Infantry
- 56th North Carolina Infantry
- 56th Ohio Infantry
- 56th Pennsylvania Infantry
- 56th Punjabi Rifles (Frontier Force)
- 56th Regiment Indiana Infantry
- 56th Squadron (disambiguation)
- 56th United States Colored Infantry Regiment
- 56th Virginia Infantry
- British Indian Army
- Canadian Army
- Russian Airborne Troops
- United States Army