18th Regiment

18th Regiment or 18th Infantry Regiment may refer to:


 * 18th Infantry Regiment (Imperial Japanese Army)
 * 18th Alpini Regiment, a unit of the Italian Army
 * 18 (UKSF) Signal Regiment, a unit of the British Army
 * 18th Royal Hussars, a unit of the British Army
 * 18th Infantry (British Indian Army), a unit of the British Indian Army
 * 18th Infantry Regiment (United States), a unit of the United States Army
 * 18th Marine Regiment (United States), a unit of the United States Marine Corps
 * Royal Irish Regiment (1684–1922) was formerly the 18th Regiment of Foot


 * American Civil War regiments :


 * Confederate (Southern) Army regiments
 * 18th Regiment Alabama Infantry
 * 18th Arkansas Infantry Regiment (Carroll's)
 * 18th Arkansas Infantry Regiment (Marmaduke's)
 * 18th Georgia Volunteer Infantry
 * 18th North Carolina Infantry
 * 18th Virginia Cavalry
 * 18th Virginia Infantry


 * Union (Northern) Army regiments
 * 18th U.S. Colored Infantry
 * 18th Connecticut Infantry Regiment
 * 18th Illinois Volunteer Infantry Regiment
 * 18th Iowa Volunteer Infantry Regiment
 * 18th Regiment Indiana Infantry
 * 18th Regiment Massachusetts Volunteer Infantry
 * 18th Michigan Volunteer Infantry Regiment
 * 18th Missouri Volunteer Infantry
 * 18th New Hampshire Volunteer Infantry
 * 18th New York Volunteer Infantry
 * 18th Kansas Militia Infantry Regiment
 * 18th Regiment Kentucky Volunteer Infantry
 * 18th Ohio Infantry
 * 18th Vermont Volunteer Infantry Regiment
 * 18th Wisconsin Volunteer Infantry Regiment