Lieutenant[nb 1] (abbreviated Lt, LT, LT(N), Lieut and LEUT, depending on nation) is a commissioned officer rank in many nations' navies. It is typically the most senior of junior officer ranks. The rank's insignia usually consists of two medium gold braid stripes and often the uppermost stripe features a loop or executive curl.
The now immediately senior rank of lieutenant commander was formerly a senior naval lieutenant rank. Many navies also use a subordinate rank of sub-lieutenant. The appointment of "first lieutenant" in many navies is held by a senior lieutenant.
Since at least 1580 the lieutenants in a ship had been the officers immediately subordinate to the captain. Before the English Restoration lieutenants were appointed by their captains, and this inevitably led to abuses and to the widespread appointment of men of insufficient qualification. In 1677 Samuel Pepys introduced the first examination for lieutenant, and it is from the date of this examination that their seniority was set.
Lieutenants were numbered by their seniority within the ship, so that a frigate which was entitled to three would have a first lieutenant, a second lieutenant, and a third lieutenant. A first-rate was entitled to six, and they were numbered accordingly. At first a lieutenant's commission was given only for the ship in which he served, but after the loss of HMS Wager in 1741 and the subsequent mutiny, lieutenants were given full commissions upon passing their examination.
During the early days of the naval rank, a lieutenant might be very junior indeed, or might be on the cusp of promotion to captain; by modern standards he might rank with any army rank between second lieutenant and lieutenant colonel. As the rank structure of navies stabilised, and the ranks of commander, lieutenant commander and sub-lieutenant were introduced, the naval lieutenant came to rank with an army captain (NATO OF-2 or US O-3).
In the United States Navy, promotion to lieutenant is governed by Department of Defense policies derived from the Defense Officer Personnel Management Act of 1980. DOPMA guidelines suggest 95% of lieutenant junior grade should be promoted to lieutenant after serving a minimum of two years at their present rank.
The insignia of a lieutenant in many navies, including the Royal Navy, consists of two medium gold braid stripes (top stripe with loop) on a navy blue or black background. This pattern was copied by the United States Navy and various air forces for their equivalent ranks grades, except that the loop is removed. (see flight lieutenant).
The first lieutenant (1st Lt or 1LT) in the Royal Navy and other Commonwealth navies, 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. Although lieutenants are no longer numbered by seniority, the post of "first lieutenant" remains.
In minor war vessels, destroyers and frigates the first lieutenant (either a lieutenant or lieutenant commander) 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 (normally a lieutenant commander) 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.
In the US Navy or US Coast Guard the billet of first lieutenant describes the officer in charge of the deck department or division, depending upon the size of the ship. In smaller ships with only a single deck division, the billet is typically filled by an ensign while in larger ships with a deck department, consisting of multiple subordinate divisions, the billet may be filled by a lieutenant commander. On submarines and smaller Coast Guard cutters the billet of first lieutenant may be filled by a petty officer.
- "Officer Ranks in the Royal Navy - Lieutenant". Royal Naval Museum. Retrieved 2008-10-11.
- Gentlemen and Tarpaulins, by J D Davies, Oxford University Press, 1991, ISBN 978-0-19-820263-9, p.40
- "Uniforms and Badges of Rank - Royal Navy website". Retrieved 2008-10-05.
|Commissioned officer ranks of the British Armed Forces|
|NATO rank code||Student Officer||OF-1||OF-2||OF-3||OF-4||OF-5||OF-6
|Royal Navy||O Cdt||Mid||SLt||Lt||Lt Cdr||Cdr||Capt||Cdre||RAdm
|Adm of the Fleet|
|Royal Marines||2Lt||Lt||Capt||Maj||Lt Col||Col||Brig||Maj-Gen||Lt-Gen||Gen
|Army||O Cdt||2Lt||Lt||Capt||Maj||Lt Col||Col||Brig||Maj-Gen
|Royal Air Force||OC / SO||APO / Plt Off||Fg Off||Flt Lt||Sqn Ldr||Wg Cdr||Gp Capt||Air Cdre||AVM||Air Mshl||Air Chf Mshl
|United States commissioned officer and officer candidate ranks|
|Pay grade / Branch of service||Officer
|Air Force||Cadet / OT / OC||2d Lt||1st Lt||Capt||Maj||Lt Col||Col||Brig Gen||Maj Gen||Lt Gen||Gen||GAF|||
|Army||CDT / OC||2LT||1LT||CPT||MAJ||LTC||COL||BG||MG||LTG||GEN||GA||GAS|
|Marine Corps||Midn / Cand||2ndLt||1stLt||Capt||Maj||LtCol||Col||BGen||MajGen||LtGen||Gen|||||
|Navy||MIDN / OC||ENS||LTJG||LT||LCDR||CDR||CAPT||RDML||RADM||VADM||ADM||FADM||AN|
|Coast Guard||CDT / OC||ENS||LTJG||LT||LCDR||CDR||CAPT||RDML||RADM||VADM||ADM|||||
|Public Health Service||[OC]||ENS||LTJG||LT||LCDR||CDR||CAPT||RADM||RADM||VADM||ADM|||||
Unofficial 1945 proposal for General of the Armies insignia; John J. Pershing's GAS insignia: ; George Dewey's AN insignia:
 Rank used for specific officers during World War II and Korea only, not permanent addition to rank structure
 Grade is authorized by the U.S. Code for use but has not been created
 Grade has never been created or authorized
|United States warrant officer ranks|
|Public Health Service|||||||||||
|National Oceanic and
 Grade is authorized for use by U.S. Code but has not been created
 Grade never created or authorized