First lieutenant is acommissioned officermilitary rank in manyarmed forces; in some forces, it is anappointment.

The rank oflieutenant hasdifferent meanings in different military formations, but in most forces it is sub-divided into a senior (first lieutenant) and junior (second lieutenant) rank.

In navies, while certain rank insignia may carry the name lieutenant, the term may also be used to relate to a particular post or duty, rather than a rank.

InIndonesia, "first lieutenant" is known asLetnan Satu (Lettu), Indonesian National Armed Forces uses this rank across all three of its services. It is just above the rank ofsecond lieutenant and just below the rank ofcaptain.

In theIsrael Defense Forces, the rank abovesecond lieutenant is simplylieutenant (Segen). The rank of (קצין מקצועי אקדמאי (קמ"א (katsín miktsoí akademai or "kama"), a professional academic officer (that is, a medical, dental or veterinary officer, a justice officer or a religious officer), is equivalent to a professional officer of the second class in the reserve and equivalent to first lieutenant.^{[citation needed]}

In theBritish Army andRoyal Marines, the rank abovesecond lieutenant is simplylieutenant (pronouncedlef-tenant), with no ordinal attached.

Before 1871, when the whole British Army switched to using the current rank of "lieutenant", theRoyal Artillery,Royal Engineers andfusilierregiments used "first lieutenant" and "second lieutenant".

Thefirst lieutenant (often abbreviated "1st Lt") in aRoyal 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 thesecond-in-command, unless the ship was complemented with acommander. Although lieutenants are no longer ranked by seniority, the post of "first lieutenant" remains. In minor war vessels,destroyers,frigates, andsubmarines, thefirst lieutenant is second in command,executive officer (XO) and head of the executive branch; in larger ships where a commander of the warfare specialization is appointed as the executive officer, afirst lieutenant is appointed as their deputy. The post offirst lieutenant in ashore establishment carries a similar responsibility to thefirst lieutenant of acapital ship. Colloquial terms in theRoyal Navy for thefirst lieutenant include "number one", "the jimmy" (or "jimmy the one") and "James the First" (a back-formation referring toJames I of England).^[1] The first lieutenant may hold the rank ofsub-lieutenant, lieutenant orlieutenant-commander.

First lieutenant
U.S. Army,U.S. Marine Corps,U.S. Air Force, andU.S. Space Force insignia of the rank of first lieutenant. Style and method of wear vary between the services.
Shoulder boards
Country	United States
Service branch	U.S. Army  U.S. Marine Corps  U.S. Air Force  U.S. Space Force
Abbreviation	1LT(Army) 1stLt(Marine Corps) 1st Lt(Air Force and Space Force)
Rank group	Company grade officer
NATOrank code	OF-1
Pay grade	O-2
Next higher rank	Captain
Next lower rank	Second lieutenant
Equivalent ranks	Lieutenant (junior grade)

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In theU.S. Army,U.S. Marine Corps,U.S. Air Force, andU.S. Space Force, a first lieutenant is a juniorcommissioned officer. It is just above the rank ofsecond lieutenant and just below the rank ofcaptain. It is equivalent to the rank oflieutenant (junior grade) in the otheruniformed services.

Promotion to first lieutenant is governed by Department of Defense policies derived from theDefense Officer Personnel Management Act of 1980. DOPMA guidelines suggest all "fully qualified" officers should be promoted to first lieutenant. A second lieutenant (grade O-1) is usually promoted to first lieutenant (grade O-2) after 18 months in the Army or 24 months in the Marine Corps and Air Force. The difference between the two ranks is slight, primarily being experience and a higher pay grade. 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 specialtyplatoon, or assignment as theexecutive officer for acompany-sized unit (70–250 soldiers or marines). In the Air Force, a first lieutenant may be a flight commander or section's officer in charge with varied supervisory responsibilities, including supervision of as many as 100+ personnel, although in a flying unit, a first lieutenant is a rated officer (pilot, navigator, or air battle manager) who has just finished training for his career field and has few supervisory responsibilities.

In theU.S. Navy andU.S. Coast Guard, "first lieutenant" is the name of abillet and position title, rather than rank. Officers aboard early sailing ships were the captain and a number of lieutenants. The senior among those lieutenants was known as the first lieutenant, and would have assumed command if the captain were absent or incapacitated.^[2] As modern ships have become more complex, requiring specialized knowledge of engineering, communications, and weapons, the "first lieutenant" is the officer in command of thedeck department responsible forline handling duringmooring andunderway replenishment. On smaller ships, the officer of the "first lieutenant" billet holds the rank oflieutenant, junior grade orensign. On larger vessels, the position of "first lieutenant" is held by a lieutenant or, in the case of extremely large warships such as cruisers oraircraft carriers, the position of "first lieutenant" may be held by alieutenant commander or evencommander. However, onsubmarines and in aircraft squadrons, where the deck department may only have a few junior sailors, the "first lieutenant" billet may be filled by a first-classpetty officer orchief petty officer. What is known in the U.S. Navy as the "first lieutenant division" is usually composed of junior sailors (E-3 and below) who are completing their ninety days of temporary assigned duty, or TAD, that all enlisted personnel are required to perform when initially assigned to a command. The primary mission of the division is servicing, cleaning, organizing and inventorying items within a command.^[3][4]

The term "first lieutenant" had a dual meaning in theUnited States Revenue Cutter Service (known until 1894 as the United States Revenue-Marine). The position title of first lieutenant was held by a junior officer who was in charge of deck operations and gunnery. The rank of first lieutenant was the equivalent of lieutenant in the current rank structure of the U.S. Coast Guard, U.S. Navy,United States Public Health Service Commissioned Corps, andNational Oceanic and Atmospheric Administration Commissioned Officer Corps. The next senior officer ranking above first lieutenant was captain and the next two lower officer ranks were second andthird lieutenant, respectively. When the Revenue Cutter Service merged with theUnited States Life-Saving Service to form the U.S. Coast Guard in 1915, the rank of first lieutenant carried over into Coast Guard and remained in use until 1918, when the Coast Guard adopted the rank structure of the U.S. Navy.^[5]

• 
  First lieutenant
  (Antigua and Barbuda Regiment)^[6]
• 
  Teniente primero
  (Argentine Army)^[7]
• 
  First lieutenant
  (Australian Army)^[8]
• 
  First lieutenant
  (Botswana Ground Force)^[9]
• 
  Primeiro tenente
  (Brazilian Army)^[10]
• 
  Primeiro tenente
  (Cape Verdean National Guard)^[11]
• 
  Primer teniente
  (Cuban Revolutionary Army)^[12]
• 
  Premierløjtnant
  (Royal Danish Army)^[13]
• 
  Primer teniente
  (Dominican Army)^[14]
• 
  Yliluutnantti
  Swedish:Premiärlöjtnant
  (Finnish Army)^[15]
• 
  First lieutenant
  (Gambian National Army)
• 
  Primeiro tenente
  (Army of Guinea-Bissau)
• 
  Letnan satu
  (Indonesian Army)^[16]
• 
  First lieutenant
  (Liberian Ground Forces)^[17]
• 
  Lieutenant en premier
  (Luxembourg Army)^[18]
• 
  1e Luitenant
  (Royal Netherlands Army)^[19]
• 
  First lieutenant
  (New Zealand Army)^[20]
• 
  Teniente primero
  (Nicaraguan Army)^[21]
• 
  Teniente primero
  (Paraguayan Army)^[22]
• 
  First lieutenant
  (Philippine Army)^[23]
• 
  First lieutenant
  (United States Army)^[24]
• 
  Teniente primero
  (National Army of Uruguay)^[25]
• 
  Primer teniente
  (Venezuelan Army)^[26]

• 
  First lieutenant
  (United States Marine Corps)^[27]

• 
  Primeiro-tenente
  (Cape Verdean Coast Guard)^[28]

• 
  First lieutenant
  (Botswana Defence Force Air Wing)^[9]
• 
  First lieutenant
  (United States Air Force)

• 
  First lieutenant
  United States Space Force

Citations

References used

• Military ranks of the British Army
• Royal Navy appointments
• Military ranks of the United States Army
• Officer ranks of the United States Air Force
• Officer ranks of the United States Space Force
• Military ranks of the United States Marine Corps

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