III Corps
- 3 Squadron (disambiguation)
- 3rd Army (disambiguation)
- 3rd Army Corps (Armenia)
- 3rd Army Corps (Azerbaijan)
- 3rd Army Corps (France)
- 3rd Army Corps (Italy)
- 3rd Army Corps (Russia)
- 3rd Army Corps (Russian Empire)
- 3rd Army Corps (Ukraine)
- 3rd Battalion (disambiguation)
- 3rd Brigade (disambiguation)
- 3rd Corps (Syria)
- 3rd Corps (Turkey)
- 3rd Corps (Vietnam People's Army)
- 3rd Division (disambiguation)
- 3rd Mechanized Corps (Soviet Union)
- 3rd Regiment (disambiguation)
- 3rd Rifle Corps
- Finnish III Corps (Continuation War)
- Finnish III Corps (Winter War)
- III (Germanic) SS Panzer Corps
- III Army Corps (Greece)
- III Army Corps (Wehrmacht)
- III Cavalry Corps (German Empire)
- III Cavalry Corps (Grande Armée)
- III Corps (Australia)
- III Corps (Bundeswehr)
- III Corps (German Empire)
- III Corps (Grande Armée)
- III Corps (India)
- III Corps (North Korea)
- III Corps (Ottoman Empire)
- III Corps (South Korea)
- III Corps (South Vietnam)
- III Corps (Union Army)
- III Corps (United Kingdom)
- III Corps (United States)
- III Panzer Corps (Germany)
- III Reserve Corps (German Empire)
- III Royal Bavarian Corps
- List of military corps by number
- Third Army Corps (Spanish–American War)
- Third Corps, Army of Northern Virginia
- Third Corps, Army of Tennessee