320th Regiment may refer to:
320th Armored Cavalry Regiment, United States 320th Cavalry Regiment, United States 320th Field Artillery Regiment, United States 320th (South Midland) Heavy Anti-Aircraft Regiment, Royal Artillery
See also 1st Battalion, 320th Field Artillery Regiment 2nd Battalion, 320th Field Artillery Regiment 3rd Battalion, 320th Field Artillery Regiment 4th Battalion, 320th Field Artillery Regiment