2nd Regiment may refer to:
Active units British Army 2nd Royal Tank Regiment
United States 2nd Aviation Regiment (United States) 2nd Air Defense Artillery Regiment 2nd Cavalry Regiment (United States) 2nd Marine Regiment (United States) 2nd Infantry Regiment (United States) 2nd Field Artillery Regiment (United States)
Australian Army 2nd Cavalry Regiment (Australia) - armoured reconnaissance unit 2nd/14th Light Horse Regiment - armoured reconnaissance unit 2nd/10th Medium Regiment, Royal Australian Artillery
French Army 2nd Combat Helicopter Regiment 2nd Foreign Engineer Regiment - French Foreign Legion Combat engineering unit 2nd Foreign Parachute Regiment - French Foreign Legion airborne commando unit 2nd Marine Infantry Parachute Regiment - airborne unit 2nd Foreign Infantry Regiment - French Foreign Legion unit
Belgian Army 2nd/4th Regiment Mounted Rifles - armoured reconnaissance unit 2nd/4th Lancers Regiment - tank unit 2nd Field Artillery Regiment/Field Artillery Battery ParaCommando
Italian Army 2nd Alpini Regiment 2nd Alpine Signal Regiment 2nd Alpine Engineer Regiment 2nd Alpine Artillery Regiment 2nd Army Aviation Support Regiment "Orione" 2nd Army Aviation Regiment "Sirio"
Canadian Army 2nd Field Regiment, Royal Canadian Artillery
Portuguese Army 2nd Lancers Regiment - Portuguese army military police unit
Former units
2nd Infantry Regiment (Lithuania) - Lithuanian interwar infantry regiment
2nd Infantry Regiment (South Korea) - Korean War unit 2nd Guards Field Artillery - Imperial German Army World War I unit 2/6th Cavalry Commando Regiment (Australia) - World War II unit 2nd Regiment of Light Cavalry Lancers of the Imperial Guard (the "Red Lancers" - a Napoleonic French unit, originally raised as the Guard Hussars of the Kingdom of Holland
Polish Army
2nd Armoured Regiment (Poland) - Polish army World War II unit 2nd Legions' Infantry Regiment 2nd Infantry Regiment (Duchy of Warsaw)
British Army
2nd East Anglian Regiment - Short lived British army unit 64th (2nd Staffordshire) Regiment of Foot - British army 2nd Tangier Regiment - British Army 65th (2nd Yorkshire, North Riding) Regiment of Foot - British army
British Indian Army
2nd Punjab Regiment - British Indian army unit 2nd Queen Victoria's Own Rajput Light Infantry - British Indian army
Yugoslavia
2nd Yugoslav Assault Regiment - Yugoslav Air Force World War II unit 2nd Training Aviation Regiment - Yugoslav Air Force post-World War II unit
Greek Army
2nd Serres Regiment, Greek army 2/21 Cretan Regiment, Greek army 2/39 Evzone Regiment, Greek army
American Civil War units Union Army 2nd United States Infantry Regiment (Civil War) 2nd United States Volunteer Sharpshooter Regiment 2nd Alabama Volunteer Infantry Regiment (African Descent) 2nd Regiment Illinois Volunteer Cavalry 2nd Regiment Indiana Cavalry 2nd Iowa Regiment 2nd Regiment Iowa Volunteer Cavalry 2nd Regiment Kansas Volunteer Infantry (African Descent) 2nd Kentucky Infantry Regiment 2nd Maine Volunteer Infantry Regiment 2nd Maryland Infantry Regiment, several units 2nd Regiment of Cavalry, Massachusetts Volunteers 2nd Regiment Massachusetts Volunteer Heavy Artillery 2nd Regiment Massachusetts Volunteer Infantry 2nd Michigan Volunteer Cavalry Regiment 2nd Michigan Volunteer Infantry Regiment 2nd Minnesota Volunteer Cavalry Regiment 2nd Nebraska Cavalry 2nd New Hampshire Volunteer Regiment 2nd New York Volunteer Infantry Regiment 2nd Ohio Infantry 2nd Regiment South Carolina Volunteer Infantry (African Descent) 2nd West Virginia Veteran Volunteer Infantry Regiment 2nd West Virginia Volunteer Cavalry Regiment 2nd West Virginia Volunteer Infantry Regiment 2nd Wisconsin Volunteer Infantry Regiment 2nd Regiment Wisconsin Volunteer Cavalry
Confederate Army 2nd Regiment Alabama Volunteer Cavalry (Confederate) 2nd Kentucky Infantry 2nd Infantry (2nd Palmetto Regiment) 2nd Maryland Infantry Regiment 2nd Virginia Infantry
American Revolutionary War units 2nd Canadian Regiment 2nd Connecticut Regiment 2nd Georgia Regiment 2nd Maryland Regiment 2nd Massachusetts Regiment 2nd New Hampshire Regiment 2nd New Jersey Regiment 2nd New York Regiment 2nd North Carolina Regiment 2nd Pennsylvania Regiment 2nd Rhode Island Regiment 2nd South Carolina Regiment 2nd Virginia Regiment 2nd Albany County Militia Regiment
Spanish–American War units 2nd Oregon Volunteer Infantry Regiment 2nd Virginia Volunteer Infantry (1898)
Others Nevers' 2nd Regiment Band
See also Second Division (disambiguation)