The list of ship launches in 1791 includes a chronological list of some ships launched in 1791.

Date	Country	Builder	Location	Ship	Class	Notes
7 January	Great Britain	Nicholas Phillips	Chatham Dockyard	Rattlesnake	Hound-class sloop	For Royal Navy.[1]
3 March	France		Brest	Aréthuse	Frigate	For French Navy.
22 March	Russia	S. I. Afanaseyev	Saint Petersburg	Bogoiavlenie Gospodne	Third rate	For Imperial Russian Navy.[2]
March	United States	Patrick Dennis		Vigilant	Cutter	For Revenue Cutter Service.
4 April	Russia	I. V. Dolzhnikov	Rogozhskaya	Soshestvie Sviatogo Dukha	Pyotr Apostol-class frigate	For Imperial Russian Navy.[3]
9 April	United States		Baltimore, Maryland	Active	Cutter	For Revenue Cutter Service.
16 April	Denmark-Norway		Arodsand	Kronprindsesse Maria	Prindsesse Sophia Frederica-class ship of the line	For Dano-Norwegian Navy.[4]
23 April	Great Britain	Perry & Co.	Blackwall Yard	Providence	Sloop-of-War	For Royal Navy.
4 May	Great Britain	Henry Adams	Buckler's Hard	Beaulieu	Fifth rate	For Royal Navy.[5]
6 May	Russia	S. I. Afanaseyev	Kherson	Sviataia Troitsa	Third rate	For Imperial Russian Navy.[6]
18 May	France		Rochefort	Hélène	Charmante-class frigate	For French Navy.[7]
21 May	New Spain	Manuel Bastarrachea	San Blas	Mexicana	Goleta	For Spanish Navy.
24 May	Russia	M. D. Portnov	Archangelsk	Arkhangel Mikhail	Arkhangel Mikhail-class frigate	For Imperial Russian Navy.[8]
24 May	Russia	M. D. Portnov	Arkhangelsk	Arkhangel Rafail	Arkhangel Mikhail-class frigate	For Imperial Russian Navy.[9]
28 May	Russia	M. D. Portnov	Arkhangelsk	Garf Orlov	Aziia-class ship of the line	For Imperial Russian Navy.[10]
24 May	Russia	M. D. Portnov	Arkhangelsk	Pamiat Evstafii	Iaroslav-class ship of the line	For Imperial Russian Navy.[11]
28 May	France		Toulon	Pompée	Téméraire-class ship of the line	For French Navy.
31 May	France		Brest	Suffren	Téméraire-class ship of the line	For French Navy.
Unknown date	Russia	A. P. Sokolov	Nicholaieff	Grigory Velikiia Armenii	Fourth rate	For Imperial Russian Navy.[12]
29 June	Great Britain	Newland	Northam	Mount Royal	Brig	For private owner.[13]
7 July	United States		Philadelphia, Pennsylvania	General Green	Cutter	For Revenue Cutter Service.
10 July	Russia	I. V. Dolzhnikov	Rogozhskaya	Kazanskaya Bogoroditsa	Pyotr Apostol-class frigate	For Imperial Russian Navy.[14]
16 July	Russia	Fursov	Taganrog	Ioann Zlatoust	Fifth rate	For Imperial Russian Navy.[15]
20 July	France		Toulon	Dauphin Royal	Océan-class ship of the line	For French Navy.
23 July	United States	Searle & Tyler	Newburyport, Massachusetts	Massachusetts	Schooner	For Revenue Cutter Service.
July	Republic of Venice			Giasone	Cutter	For Venetian Navy.[16]
15 August	Great Britain	W. Richards	Hythe	Georgiana	Merchantman	For St. Barbe & Co.
19 August	France		Rochefort	Le Pyrrhus	Third rate	For French Navy.[17]
24 August	United States			Scammel	Schooner	For Revenue Cutter Service.
20 August	Kingdom of Naples		Naples	Minerve	Frigate	For Royal Neapolitan Navy.
30 August	France		Toulon	Sibylle	Hébé-class frigate	For French Navy.
10 September	Denmark-Norway	Ernst Wilhelm Stibolt	Copenhagen	Lougen	Lougen-class brig	For Dano-Norwegian Navy.
12 September	Spain	Reales Astilleros de Esteiro	El Ferrol	Reina María Luisa	Santa Ana-class ship of the line	For Spanish Navy.
12 September	France		Lorient	Thémistocle	Téméraire-class ship of the line	For French Navy.
24 September	Denmark-Norway	Ernst Wilhelm Stibolt	Tønsberg	Sarpen	Lougen-class brig	For Dano-Norwegian Navy.
28 September	Portugal	Torcato Jose Clavina	Lisbon	Rainha de Portugal	Third rate	For Portuguese Navy.[18]
28 September	Portugal		Lisbon	Serpente do Mar	Sixth rate	For Portuguese Navy.[19]
29 September	Great Britain	Marmaduke Stalkart	Rotherhithe	Comet	Merchantman	For B. Daubuz.
September	Republic of Venice	Girado Manao	Venice	Medusa	Palma-class Frigate	For Venetian Navy.[20]
1 October	Denmark-Norway	Ernst Wilhelm Stibolt	Copenhagen	Glommen	Lougen-class brig	For Dano-Norwegian Navy.[21]
6 October	State of Brazil		Bahia	Princesa Carlota	Fifth rate	For Portuguese Navy.[22]
25 October	France		Brest, France	Concorde	Nymphe-class frigate	For French Navy.
25 November	France		Lorient	Sémillante	Sémillante-class frigate	For French Navy.
28 November	Great Britain	Barnard	Deptford	Indian Trader	Merchantman	For John Brickwood.
9 December	Spain		Carthagena	Conquistador	Third rate	For Spanish Navy.[23]
22 December	Cuba	Landa Romero	Havana	Ceres	Fifth rate	For Spanish Navy.[24]
22 December	Cuba		Havana	Infante Don Pelayo	Third rate	For Spanish Navy.[25]
Autumn	United States		Boston, Massachusetts	Margaret	Full-rigged ship	For James & Thomas Lamb, James Magee, Thomas Handasyd Perkins and Russell Sturgis.
Unknown date	Russia	I. Ivanov	Taganrog	Aleksei	Galley	For Imperial Russian Navy.[26]
Unknown date	Great Britain		Scarborough	Amphitrite	Merchantman	For private owner.
Unknown date	France		Dunkerque	L'Anacréon	Privateer	For privateer.[27]
Unknown date	United States		New London, Connecticut	Argus	Sloop	For Revenue Cutter Service.
Unknown date	Great Britain		Plymouth	Britannia	Merchantman	For Moore & Co.
Unknown date	Great Britain		River thames	Brunswick	West Indiaman	For T. Hibbert & Co.
Unknown date	Great Britain		Liverpool	Commerce	Merchantman	For G. Slater.
Unknown date	Spain			El Corso	Brig	For Spanish Navy.
Unknown date	Spain		Puerto Mahón	Esmeralda	Frigate	For Spanish Navy.
Unknown date	Great Britain	John Nicholson	Chatham	Goodwill	Lighter	For Royal Navy.[28]
Unknown date	Kingdom of Sicily	Antonion Imbert	Castellamare del Golfo	Guiscard	Third rate	For Royal Sicilian Navy.[29]
Unknown date	Great Britain		Bristol	Harpooner	Whaler	For J. Caves.
Unknown date	Great Britain		Bristol	Hebe	Merchantman	For Jacks & Co.
Unknown date	France		Bordeaux	Indispensable	Merchantman	For private owner.
Unknown date	Great Britain	Randall & Brent	Rotherhithe	Lady Harewood	West Indiaman	For Elliott & Co.
Unknown date	Great Britain		River Thames	London Packet	Merchantman	For John Toone.
Unknown date	Ireland		Galway	Minerva	Merchantman	For Burk & Co.
Unknown date	Great Britain		Whitby	Selby	Ship-sloop	For Mr Woodcock.
Unknown date	France			St. Jean de Lone	East Indiaman	For private owner.
Unknown date	Great Britain	Reynolds & Co	Whitby	Sylph	Merchantman	For Nathaniel Langbourne, William Holt, and W. Reynolds.
Unknown date	Great Britain		Liverpool	Union	Slave ship	For George Hault, John Ratcliffe, and William Thompson.
Unknown date	United States			Vigilant	Schooner	For Revenue Cutter Service.
Unknown date	Great Britain		River Thames	Westmoreland	Merchantman	For private owner.
Unknown date	Great Britain	Edward Sison	Sheerness Dockyard	No.2 longboat	Longboat	For Royal Navy.[30]
Unknown date	France			Name unknown	Merchantman	For private owner.
Unknown date	United States			Name unknown	Merchantman	For private owner.
Unknown date	United States			Name unknown	Merchantman	For private owner.
Unknown date	France			Name unknown	Merchantman	For private owner.
Unknown date	Spain			Name unknown	Merchantman	For private owner.
Unknown date			America	Name unknown	Merchantman	For private owner.
Unknown date	Spain			Name unknown	Merchantman	For private owner.
Unknown date	France		Nantes	Name unknown	Brig	For private owner.
Unknown date	Russia			Unnamed	Schooner	For Imperial Russian Navy.[31]