21st Regiment may refer to:

Infantry regiments

* 21 Regiment Special Air Service, a unit of the British Army *

21st Foot The Royal Scots Fusiliers was a line infantry regiment of the British Army that existed from 1678 until 1959 when it was amalgamated with the Highland Light Infantry (City of Glasgow Regiment) to form the Royal Highland Fusiliers (Princess Ma ...

, a former regiment of the British Army *

21st Infantry Regiment (Thailand) The 21st Infantry Regiment, Queen Sirikit's Guard ( th, :th:กรมทหารราบที่ 21 รักษาพระองค์, กรมทหารราบที่ 21 รักษาพระองค์ ในสมเด็จ� ...

, a unit of the Royal Thai Army *

21st Infantry Regiment (United States) The 21st Infantry Regiment ("Gimlet") Is a United States Army infantry regiment. The 1st Battalion currently exists as part of 2nd Infantry Brigade Combat Team, 25th Infantry Division and the 3rd Battalion of the 1st Infantry Brigade Combat Te ...

, a unit of the United States Army *

21st Punjabis The 21st Punjabis were an infantry regiment of the British Indian Army. It was raised in 1857, as the 11th Regiment of Punjab Infantry. It was designated as the 21st Punjabis in 1903 and became 10th (Training) Battalion of 14th Punjab Regiment in 1 ...

, a unit of the British Indian Army *

21st Marine Infantry Regiment The 21st Marine Infantry Regiment (french: 21e Régiment d'Infanterie de Marine, 21e RIMa) is a unit of the French military issued by filiation from the 2e RIC. Creation and different nominations * 1831: creation of the 2nd Marine Infantry Re ...

, a unit of the French Marines *

21st Marine Regiment (United States) The 21st Marine Regiment (21st Marines) was an infantry regiment of the United States Marine Corps. Commissioned for service during World War II, the regiment fought in the battles of Bougainville, Guam and Iwo Jima. It fell under the command of ...

, a unit of the United States Marine Corps

American Revolutionary War regiments

* 21st Continental Regiment

American Civil War regiments

21st Iowa Volunteer Infantry Regiment {{Infobox military unit , unit_name= 21st Iowa Infantry Regiment , image=Flag of Iowa.svg , image_size = 100 , caption=Iowa state flag , dates= August 25, 1862, to July 15, 1865 , country= United States , allegiance= Union , branch= Infantry , equ ...

21st Illinois Volunteer Infantry Regiment The 21st Regiment Illinois Volunteer Infantry was a volunteer infantry regiment that served in the Union Army during the American Civil War. History The regiment was raised under the Ten Regiment Bill, which anticipated Federal troop requirements ...

21st Maine Volunteer Infantry Regiment The 21st Maine Infantry Regiment was an infantry regiment that served in the Union Army during the American Civil War. Service The 21st Maine Infantry was organized in Augusta, Maine and mustered in October 14, 1862, for nine months' service unde ...

21st Michigan Volunteer Infantry Regiment {{Infobox military unit , unit_name= 21st Michigan Infantry Regiment , image=21st Michigan Infantry - NARA - 524713.jpg , caption= , dates= September 9, 1862, to June 8, 1865 , country= {{flag, United States , allegiance= Union , branch= Infantry , ...

21st Mississippi Infantry Regiment The 21st Regiment, Mississippi Infantry was a Confederate infantry regiment from Mississippi in the American Civil War. The regiment was involved in several well documented battles including the battles of Antietam, Chancellorsville, Gettysburg an ...

21st Ohio Infantry The 21st Ohio Infantry Regiment was an infantry regiment in the Union Army during the American Civil War. Mostly an all-volunteer unit, with the exception of a few draftees, the 21st Ohio served for both ninety-day and three-year enlistments and f ...

21st Kansas Militia Infantry Regiment The 21st Kansas Militia Infantry was an infantry regiment that served in the Union Army during the American Civil War. Service The 21st Kansas Militia Infantry was called into service on October 9, 1864. It was disbanded on October 29, 1864. Det ...

21st Regiment Kentucky Volunteer Infantry The 21st Kentucky Infantry Regiment was an infantry regiment that served in the Union Army during the American Civil War. Service The 21st Kentucky Infantry Regiment was organized at Camp Hobson, near Greensburg, Kentucky and Camp Ward, Kentucky ...

21st Regiment Massachusetts Volunteer Infantry The 21st Massachusetts Infantry Regiment was an infantry regiment in the Union Army during the American Civil War. It was organized in Worcester, Massachusetts and mustered into service on August 23, 1861. After garrison duty at the United Stat ...

21st Wisconsin Volunteer Infantry Regiment The 21st Wisconsin Infantry Regiment was a volunteer infantry regiment that served in the Union Army during the American Civil War. They were assigned for their entire war service to XIV Corps, operating in the western theater of the war. Serv ...

Cavalry regiments

21st Lancers The 21st Lancers (Empress of India's) was a cavalry regiment of the British Army, raised in 1858 and amalgamated with the 17th Lancers in 1922 to form the 17th/21st Lancers. Perhaps its most famous engagement was the Battle of Omdurman, where W ...

, a unit of the British Army

Engineer regiments

21st Construction Regiment (Australia) The 21st Construction Regiment (21 CR) was a construction engineer regiment of the Australian Army Reserve. Part of the 5th Brigade, the regiment was formed in 1950 and was based in New South Wales where it provided support to the 2nd Division. ...

, a former unit of the Australian Army's Engineers *

21 Engineer Regiment (United Kingdom) 21 Engineer Regiment RE is a regiment of the British Army's Royal Engineers. It is based at Claro Barracks, Ripon, Catterick Garrison in Yorkshire. History 21 Engineer Regiment was first formed in 1949 at Holzminden to fulfill 7th Armoured Di ...

, a unit of the British Army's Royal Engineers

Infantry regiments

American Revolutionary War regiments

American Civil War regiments

Cavalry regiments

Engineer regiments

See also