29 Military units and formations established in 1913

The 1st Marine Regiment is an infantry regiment of the United States Marine Corps based at Marine Corps Base Camp Pendleton, California. The regiment, sometimes known as "Inchon" or Regimental Combat Team 1, falls under the command of the 1st Marine Division and the I Marine Expeditionary Force.

The 1st Reconnaissance Squadron is a United States Air Force squadron, assigned to the 9th Operations Group, Beale Air Force Base, California.

The 1st Squadron is a fighter squadron in the Air Component of the Belgian Armed Forces. It is part of the 2nd Tactical Wing and operates F-16 Fighting Falcons.

The 3rd Battle Squadron was a naval squadron of the British Royal Navy consisting of battleships and other vessels, active from at least 1914 to 1945. The 3rd Battle Squadron was initially part of the Royal Navy's Home Fleet. During the First World War, the Home Fleet was renamed the Grand Fleet. During the Second World War, the squadron covered Atlantic convoys.

The 9th Motorized Infantry Brigade is a motorized infantry brigade of the Hellenic Army. Headquartered in Kozani and subordinated to the III Army Corps, it was formed from the former 9th Infantry Division on 1 April 1998.

The 10th Infantry Regiment "(Χ ΜΠ)" is a motorized infantry Regiment of the Hellenic Army. Headquartered in Serres and subordinated to the III Army Corps, it was formed from the former 10th Infantry Division on 1 July 2004.

The 11th Infantry Division was an infantry division of the Hellenic Army.

The 12th Mounted Rifles were a light cavalry regiment of the Royal Prussian Army. The regiment was formed 1 October 1913 in St. Avold.

The 13th Infantry Division was an infantry division of the Hellenic Army.

The 13th Special Operations Command "Sacred Band" is an umbrella unit of the Hellenic Army's special operation forces.

The 13th Mounted Rifles were a light cavalry regiment of the Royal Prussian Army. The regiment was formed 1 October 1913 in Saarlouis.

The 29th Mechanized Infantry Brigade "Pogradec" is a mechanized infantry brigade of the Hellenic Army. It is headquartered in Komotini as part of IV Army Corps.

The 34th Mechanized Infantry Brigade is a mechanized infantry brigade of the Hellenic Army. It is headquartered in Assiros and subordinated to the 2nd Mechanized Infantry Division.

The 102nd Cavalry Regiment is a regiment of the United States Army first established in 1913 and which saw service in World War II.

The 369th Infantry Regiment, formerly known as the 15th New York National Guard Regiment and commonly referred to as the Harlem Hellfighters, was an infantry regiment of the New York Army National Guard during World War I and World War II. The Regiment consisted mainly of African Americans, though it also included several Puerto Rican Americans during World War II. With the 370th Infantry Regiment, it was known for being one of the first African American regiments to serve with the American Expeditionary Forces during World War I.

Royal Air Force Calshot or more simply RAF Calshot was initially a seaplane and flying boat station, and latterly a Royal Air Force marine craft maintenance and training unit. It was located at the end of Calshot Spit in Southampton Water, Hampshire, England, at grid reference SU487024. It was the main seaplane/flying boat development and training unit in the UK, with the landing area sheltered by the mainland, to the west, north and east, and the Isle of Wight, a few miles away to the south on the other side of the Solent, where seaplanes and flying boats were mass-produced by Saunders-Roe. It closed in 1961. Much of the former base has been preserved, with most of the site now being occupied by the RNLI.

Fliegerstaffel 1 was a professional military pilots squadron, therefore belonging to the Überwachungsgeschwader of the Swiss Air Force until its last service in 2003. At that point, it was equipped with Northrop F-5 and used the military airfield of Turtmann as a designated war base. Fliegerstaffel 1 carried a stylized Vogel Rokh as its coat of arms, a red background and a white figure 1 completed their emblem.

The I Army Corps was an army corps of the Hellenic Army, founded in December 1913. Originally based in Athens and covering southern Greece, since 1962 it was responsible for covering Greece's northwestern borders. It was disbanded in 2013.

The II Army Corps was an army corps of the Hellenic Army. Established in 1913, it took part in all subsequent wars of Greece. Since 1998 the corps functioned as a strategic reserve force, and comprised the Army's special forces and army aviation units, as well as mechanized infantry. It was disbanded on 29 November 2013.

The Irish Fusiliers of Canada was an infantry regiment of the Canadian Army.

The Irish Volunteers, sometimes called the Irish Volunteer Force or Irish Volunteer Army, was a military organisation established in 1913 by Irish nationalists. It was ostensibly formed in response to the formation of the Ulster Volunteers in 1912, and its declared primary aim was "to secure and maintain the rights and liberties common to the whole people of Ireland". The Volunteers included members of the Gaelic League, Ancient Order of Hibernians and Sinn Féin, and, secretly, the Irish Republican Brotherhood (IRB). Increasing rapidly to a strength of nearly 200,000 by mid-1914, it split in September of that year over John Redmond's commitment to the British War effort, with the smaller group retaining the name of "Irish Volunteers".

The IV Army Corps is an army corps of the Hellenic Army. Established before the First World War, it served in all conflicts Greece participated in until the German invasion of Greece in 1941. Re-established in 1976, it has been guarding the Greco-Turkish land border along the Evros River, and is the most powerful formation in the Hellenic Army.

The General Directorate of Border Guard is a Saudi agency responsible for guarding land and sea borders of the Kingdom. Awwad Eid Al-Aradi Al-Balawi is the Directorate general of Saudi Arabian Border Guards.

Number 5 Squadron is a squadron of the Royal Air Force. First formed in July 1913, the squadron served throughout the First World War, holding the distinction of gaining the first loss and kill for the Royal Flying Corps. No. V Squadron relocated to India in 1920 where it remained during the Second World War. During the Cold War, No. 5 (Fighter) Squadron flew the English Electric Lightning and Panavia Tornado F.3 before disbanding in September 2002. Since its reformation on 1 April 2004, it has operated the Raytheon Sentinel R.1 Airborne STand-Off Radar (ASTOR) aircraft from RAF Waddington, Lincolnshire.

The Pretoria Regiment / Pretoria Armoured Regiment is an armoured regiment of the South African Army. As a reserve unit, it has a status roughly equivalent to that of a British Army Reserve or United States Army National Guard unit. The Regiment is stationed in the city after which it was named, Pretoria. It is part of the South African Army Armour Formation.

The Royal Netherlands Air Force, is the military aviation branch of the Netherlands Armed Forces. It was created in 1953; its ancestor, the Luchtvaartafdeling of the Dutch Army was founded in 1913. The aerobatic display team of the Royal Netherlands Air Force was the Solo Display Team.

The Royal Thai Air Force or RTAF is the air force of the Kingdom of Thailand. Since its establishment in 1913 as one of the earliest air forces of Asia, the Royal Thai Air Force has engaged in numerous major and minor conflicts. During the Vietnam War era, the RTAF was supplied with USAF-aid equipment.

The Saskatchewan Dragoons is a Primary Reserve armoured regiment of the Canadian Army. The unit is based in Moose Jaw. Their primary job is to assist the Regular Force in meeting Canada's military commitments. Their training and equipment closely follow that of the Regular Force, which the Reserves are called upon to assist increasingly often. The Saskatchewan Dragoons are part of 3rd Canadian Division's 38 Canadian Brigade Group.