18th Cavalry may refer to:
Divisions 18th Cavalry Division (Soviet Union)
Regiments and battalions 18th Cavalry (India) 18th Cavalry Regiment (United States) 18th Corps Cavalry Regiment
American Civil War units Union Army 18th Pennsylvania Cavalry Regiment
Confederate Army 18th Arkansas Cavalry Battalion 18th Mississippi Cavalry Battalion 18th Virginia Cavalry Regiment
See also 18th Division (disambiguation) 18th Regiment (disambiguation) 18th (disambiguation)