First Lieutenant is a military rank.

The rank of Lieutenant has different meanings in different military formations (see comparative military ranks), but the majority of cases it is common for it to be sub-divided into a senior (First Lieutenant) and junior (Second Lieutenant) rank. In navies it may relate to a particular post rather than a rank.

United Kingdom

British Army

In the British Army and Royal Marines, the rank above Second Lieutenant is simply Lieutenant, with no ordinal attached.

Before 1871, when the whole British Army switched to using the current rank of "Lieutenant", the Royal Artillery, Royal Engineers and Fusilier regiments used "First Lieutenant" and "Second Lieutenant".

Royal Navy

The First Lieutenant (1st Lt) in a Royal Navy ship is a post or appointment, rather than a rank.

Historically the lieutenants in a ship were ranked in accordance with seniority, with the most senior being termed the First Lieutenant and acting as the second-in-command, unless the ship was complemented with a Commander. Although lieutenants are no longer ranked by seniority, the post of "First Lieutenant" remains. In Minor War Vessels, Destroyers and Frigates the First Lieutenant is second in command, Executive Officer (XO) and head of the executive branch; in larger ships where a Commander of the warfare specialisation is appointed as the Executive Officer, a First Lieutenant is appointed as his deputy. The post of First Lieutenant in a shore establishment carries a similar responsibility to the First Lieutenant of a Capital Ship.

Colloquial terms in the Royal Navy for the First Lieutenant include "Number One", "the Jimmy" (or "Jimmy the One") and "James the First" (a back-formation referring to James I of England).

United States

U.S. Army, U.S. Marine Corps and U.S. Air Force

In the U.S. Army, Marine Corps, and Air Force, a First Lieutenant (O-2) is the second-lowest ranking commissioned officer. It is one grade above the rank of Second Lieutenant (O-1) and one grade below a Captain (O-3). Second Lieutenants are usually promoted to First Lieutenant after 18 months (Army) or 24 months (Air Force and Marine Corps) of commissioned service.

The difference between the two ranks of Lieutenant is slight, primarily being experience and higher pay. It is not uncommon to see officers moved to positions requiring more experience after promotion to First Lieutenant. For example, in the Army and Marine Corps these positions can include leading a specialty platoon, or assignment as the Executive Officer for a company-sized unit (65-150 soldiers). In the Air Force, a First Lieutenant may be a flight commander, although in an operational unit, a First Lieutenant is generally a rated officer (pilot, navigator, or air battle manager) who has just finished training for his career field and has few supervisory responsibilities.

U.S. Navy and U.S. Coast Guard

In the U.S. Navy and Coast Guard, First Lieutenant is a position title, instead of a rank. It is held by the officer in command of the deck department. On smaller ships, the First Lieutenant holds the rank of Lieutenant, junior grade or Ensign. On larger vessels, the position is held by a Lieutenant or, in the case of extremely large warships such as aircraft carriers, a Lieutenant Commander or even Commander. However, on submarines, where the deck department may only have a few junior sailors, the First Lieutenant may be a senior enlisted member, such as a First-Class Petty Officer or Chief Petty Officer.

Other countries

For other countries, the equivalent rank to a US Army First Lieutenant (O-2) is listed below.

• : Lomri Baridman
• : Toger
• : Primeiro Tenente
• Arabic-speaking countries except former French colonies in North Africa: Mulazim Awwal
• : Teniente Primero (army); Primer Teniente (air force)
• : Oberleutnant
• : Baş Leytenant
• : Cтарший Лейтенант (Starshiy Leytenant)
• : Lieutenant (French); Luitenant (Dutch)
• : Deda Gom
• : Poručnik
• : Primeiro Tenente
• : Cтарши Лейтенант (Starshiy Leytenant)
• : Ak-no-say-ney-tor
• : Primeiro Tenente
• Imperial China : 副軍校 (Fù jūn xiào)
• : 中尉 (Zhōngwèi)
• (Taiwan): 中尉(Chungwei)
• : Natporučnik
• : Primer Teniente
• : Ypolokhagos (army); Yposminagos (air force)
• : Nadporučík
• : Nadporučík
• : Premierløjtnant
• : Primer Teniente
• : Leitnant
• : Luutnantti
• and all other French-speaking countries: Lieutenant (Air Force/Army), Enseigne de vaisseau de première classe (Navy)
• Georgia: უფროსი ლეიტენანტი (Up’rosi Leytenanti)
• : Oberleutnant
• : Ypolokhagos (army); Yposminagos (air force)
• : Főhadnagy
• : Letnan Satu
• : ستوان یكم (Setvan Yekom)
• : Lieutenant (English); Lefteanant (Irish)
• : סגן (Segen)
• : Tenente
• : Nitō Rikui 2等陸尉(or Nii 2尉) (modern) / Chūi 中尉 (historical)
• : Старші Лейтенант (Starshiy Leytenant)
• and : 중위 (Jungwi)
• : Roithõäkäd
• : Virsleitnants
• : Vyresnysis Leitenantas
• : Premier Lieutenant
• : Leftenan
• : Upa-Senani
• : Поручник (Poručnik)
• : Ахлах дэслэгч (Ahlah deslegch)
• : Tenente
• : Eerste Luitenant
• : Teniente Primero
• : Løytnant
• : Lieutenant (Army)
• : Teniente Primero
• : First Lieutenant (English); Unang Tenyente (Filipino), Primero Tenyente
• : Porucznik
• : Tenente
• : Locotenent (current); Locotenet-Major (Warsaw Pact)
• : Cтарший Лейтенант (Starshiy Leytenant)
• : Поручник (Poručnik)
• : Nadporučík
• : Nadporočnik
• : Cтарший Лейтенант (Starshiy Leytenant)
• and all other Spanish-speaking countries except Argentina, Cuba, the Dominican Republic, Nicaragua, Paraguay and Uruguay: Teniente
• : Luitenant
• : Löjtnant
• : Oberleutnant (German); Premier Lieutenant (French); Primotenente (Italian)
• : Roi Tho
• : ملازم أول (Moulazem Awal)
• : Üsteğmen
• : Cтарший Лейтенант (Starshiy Leytenant)
• : Teniente Primero
• : Katta Leytenant
• : Trung Uy
• : Поручник (Poručnik)

References