300th
300th Airlift Squadron
300th Armored Cavalry Regiment
300th Field Artillery Regiment
300th Military Intelligence Brigade (United States)
300th Sustainment Brigade (United States)
Medal "In Commemoration of the 300th Anniversary of Saint Petersburg"
300th Rifle Division (Soviet Union)
300th Mechanized Regiment (Ukraine)
1943 300th Infantry Sabers football team
Gothenburg Exhibition
Romanov Tercentenary
818th Tank Destroyer Battalion
No. 300 Polish Bomber Squadron
Queen's Own Worcestershire Hussars
Fort Moore
Finsbury Rifles
3rd Middlesex Artillery Volunteers
Poplar and Stepney Rifles
1st Aberdeenshire Artillery Volunteers