# Captain
Captain is a commissioned officer rank used in armies, navies, and air forces, and it does not mean the same grade everywhere: in most land and air forces it is a junior officer rank, while in navies it is a senior rank equivalent to an army colonel. United States law, for example, assigns Captain to pay grade O-3 in the Army, Air Force, Marine Corps, and Space Force, and to pay grade O-6 in the Navy and Coast Guard.[1](https://www.govinfo.gov/content/pkg/USCODE-2024-title37/html/USCODE-2024-title37.htm) Both uses descend from the same root idea of a person at the head of a body of troops, whether a company on land or the crew of a warship.
| Key fact | Detail |
|---|---|
| Land forces (US) | Captain is pay grade O-3 in the Army, Air Force, Marine Corps, and Space Force; the Navy and Coast Guard equivalent is Lieutenant[1](https://www.govinfo.gov/content/pkg/USCODE-2024-title37/html/USCODE-2024-title37.htm) |
| Naval forces (US) | Captain is pay grade O-6, equivalent to an Army, Air Force, or Marine Corps colonel[1](https://www.govinfo.gov/content/pkg/USCODE-2024-title37/html/USCODE-2024-title37.htm) |
| NATO codes (UK) | Army and Royal Marines Captain is OF-2; Royal Navy Captain is OF-5, matching Army Colonel and RAF Group Captain[2](https://www.legislation.gov.uk/ukpga/2006/52/notes?view=plain) |
| Etymology | Late 14c. *capitayn*, "a leader, chief," from Old French *capitaine*, from Late Latin *capitaneus*, from Latin *caput*, "head"[3](https://www.etymonline.com/word/captain) |
| Dated senses | The military sense, an officer commanding a company between major and lieutenant, is from the 1560s; the naval sense, an officer commanding a man-of-war, is from the 1550s[3](https://www.etymonline.com/word/captain) |
| British Army tenure | The rank of Captain is typically held for five to ten years[4](https://www.army.mod.uk/learn-and-explore/ranks/) |
| Title of address | Any commanding officer at sea is traditionally addressed as Captain regardless of rank[5](https://www.usni.org/magazines/proceedings/1956/november/admiral-midshipman) |
## Etymology and word history
The English word appears in the late fourteenth century as *capitayn*, meaning a leader or one who stands at the head of others, borrowed from [Old French](https://www.edgepedia.org/old-french) *capitaine*, which comes from [Late Latin](https://www.edgepedia.org/late-latin) *capitaneus*, an adjective meaning prominent or chief, built on Latin *caput*, "head."[3](https://www.etymonline.com/word/captain) The same Latin root underlies related words such as chief and chieftain.[3](https://www.etymonline.com/word/captain)
The rank senses settled at different times. The naval sense, an officer who commands a man-of-war, is recorded from the 1550s and was extended to the master or commander of a vessel of any kind by 1704; the land military sense, an officer commanding a company with the rank between major and lieutenant, is recorded from the 1560s. A verb, "act as leader to, command," dates from the 1590s, and the sporting sense, leader of a team, from 1823.[3](https://www.etymonline.com/word/captain)
## Captain as a junior land and air force rank
In the [United States Army](https://www.edgepedia.org/united-states-army), Air Force, Marine Corps, and Space Force, [Captain](https://www.edgepedia.org/captain-united-states-o-3) sits at pay grade O-3, below Major at O-4; the Navy and Coast Guard equivalent at O-3 is [Lieutenant](https://www.edgepedia.org/lieutenant).[1](https://www.govinfo.gov/content/pkg/USCODE-2024-title37/html/USCODE-2024-title37.htm) Title 10 lists Captain among the commissioned officer grades of the Air Force, after Major.[6](https://usc-cdn.house.gov/view.xhtml?edition=prelim&num=0&req=granuleid%3AUSC-prelim-title10-section9151)
The [British Army](https://www.edgepedia.org/british-army) places Captain between Major and Lieutenant in its twelve-grade officer ladder, and states that the rank is typically held for five to ten years.[4](https://www.army.mod.uk/learn-and-explore/ranks/) Under the NATO equivalence codes used by the United Kingdom, the army and Royal Marines Captain is OF-2, the same code as the Royal Navy Lieutenant and the Royal Air Force Flight Lieutenant.[2](https://www.legislation.gov.uk/ukpga/2006/52/notes?view=plain)
## Captain as a naval rank
The naval Captain outranks the army Captain by three grades: in United States law, [Colonel](https://www.edgepedia.org/colonel) and Captain of the Navy and Coast Guard both sit at O-6, and the equivalence table in title 10 pairs the two directly.[7](https://usc-cdn.house.gov/view.xhtml?edition=prelim&num=0&req=granuleid%3AUSC-prelim-title10-section741) A Department of Veterans Affairs orientation document notes plainly that a Navy captain is a much higher rank than an Army captain.[8](https://www.mentalhealth.va.gov/coe/cih-visn2/Documents/Provider_Education_Handouts/Military_Facts_for_Non_Military_SW_Version_3.pdf)
**Why one word covers both.** The rank grew out of the same command role in each environment: the captain was the head man of the basic fighting unit, whether a company of roughly 100 to 200 men on land or the company of a ship at sea, with lieutenants as seconds in command in both cases.[3](https://www.etymonline.com/word/captain) • [9](https://history.stackexchange.com/questions/58606/why-was-captain-named-for-2-different-ranks) As armies grew, the company stayed small and its commander stayed junior, while warships grew so large and costly that their captains accumulated rank equivalent to regimental-level officers.[7](https://usc-cdn.house.gov/view.xhtml?edition=prelim&num=0&req=granuleid%3AUSC-prelim-title10-section741)
## United States Navy history
For nearly a century Captain was the highest grade in the [United States Navy](https://www.edgepedia.org/united-states-navy); the grades above it, from commodore upward, were proposed in 1776 but not actually established at that time.[5](https://www.usni.org/magazines/proceedings/1956/november/admiral-midshipman) The 1776 equivalence plan submitted to Congress compared a captain of 40-gun ships with an army colonel, a captain of 20-to-40-gun ships with a lieutenant colonel, and a captain of 10-to-20-gun ships with a major.[5](https://www.usni.org/magazines/proceedings/1956/november/admiral-midshipman)
In 1779 the grade was unusually inclusive: any commissioned officer in command of a warship was a permanent [Captain](https://www.edgepedia.org/captain-armed-forces). Because this gave no way to distinguish seniority within the grade, a new system kept the rank of Captain only for commanding officers of ships with forty or more guns.[5](https://www.usni.org/magazines/proceedings/1956/november/admiral-midshipman) The commanders of the twenty-to-forty-gun ships received the temporary designation Master Commandant, renamed [Commander](https://www.edgepedia.org/commander), a permanent rank, by an Act of March 3, 1837, paralleling the Army grade of lieutenant colonel; the lesser captains of ten-to-twenty-gun ships became Lieutenants Commanding, renamed Lieutenant Commander in 1862, equivalent to an army major.[5](https://www.usni.org/magazines/proceedings/1956/november/admiral-midshipman) The Navy history office records that the top grade, Post-Captain, was equal in rank to an army colonel, and that the Navy Captain remained so.[10](https://www.history.navy.mil/research/library/online-reading-room/title-list-alphabetically/w/naval-traditions-names-of-rank/officer/navy-captain.html) The British adopted Captain as an official naval title in 1747.[5](https://www.usni.org/magazines/proceedings/1956/november/admiral-midshipman)
The 1862 act that created the grades above captain was driven partly by dealings with foreign navies: United States naval officers were dealing with men of superior rank, and the new grades let American officers rank with the flag officers of foreign countries.[5](https://www.usni.org/magazines/proceedings/1956/november/admiral-midshipman)
## Rank, pay grade, and the title of address
The Defense Department distinguishes rank from pay grade such as E-1, W-2, and O-5; Captain appears in its insignia listings abbreviated CPT in the Army.[11](https://www.defense.gov/Resources/Insignia/Military-Ranks/) Independent of rank, any commanding officer of a vessel is traditionally addressed as Captain, so an officer of commander rank or below commanding a smaller ship holds the title of the office without the grade.[5](https://www.usni.org/magazines/proceedings/1956/november/admiral-midshipman)
## References
1. [U.S.C. Title 37, §201: Pay grades: assignment to; general rules, govinfo](https://www.govinfo.gov/content/pkg/USCODE-2024-title37/html/USCODE-2024-title37.htm)
2. [Armed Forces Act 2006, Explanatory Notes (NATO rank codes for RN, Army, RM, RAF), legislation.gov.uk](https://www.legislation.gov.uk/ukpga/2006/52/notes?view=plain)
3. [Captain: Etymology, Origin & Meaning, Online Etymology Dictionary](https://www.etymonline.com/word/captain)
4. [Rank Structure, The British Army](https://www.army.mod.uk/learn-and-explore/ranks/)
5. [From Admiral To Midshipman, Lieutenant Richard H. Sprince, USNI Proceedings, November 1956](https://www.usni.org/magazines/proceedings/1956/november/admiral-midshipman)
6. [10 USC 9151: Commissioned officer grades, uscode.house.gov](https://usc-cdn.house.gov/view.xhtml?edition=prelim&num=0&req=granuleid%3AUSC-prelim-title10-section9151)
7. [10 USC 741: Rank: commissioned officers of the armed forces, uscode.house.gov](https://usc-cdn.house.gov/view.xhtml?edition=prelim&num=0&req=granuleid%3AUSC-prelim-title10-section741)
8. [An Explanation of Military Ranks and Types of Organizations, U.S. Department of Veterans Affairs](https://www.mentalhealth.va.gov/coe/cih-visn2/Documents/Provider_Education_Handouts/Military_Facts_for_Non_Military_SW_Version_3.pdf)
9. [Why was 'Captain' named for 2 different ranks?, History Stack Exchange](https://history.stackexchange.com/questions/58606/why-was-captain-named-for-2-different-ranks)
10. [Navy Captain, Naval History and Heritage Command](https://www.history.navy.mil/research/library/online-reading-room/title-list-alphabetically/w/naval-traditions-names-of-rank/officer/navy-captain.html)
11. [U.S. Military Rank Insignia, U.S. Department of Defense](https://www.defense.gov/Resources/Insignia/Military-Ranks/)
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*Topic: Encyclopedia › Society and history › Conflict and security › Ranks, honours, and service traditions › Military ranks › Comparative and general rank references*
*Initially written Sep 17, 2026 · Reviewed: Oct 25, 2026 · Edited: Oct 15, 2026; Oct 25, 2026 · Last review: Oct 25, 2026*
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