# List of ship launches in 1791

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. |
| 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. |
| 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. |
| 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. |
| 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. |
| 6 May | Russia | S. I. Afanaseyev | Kherson | Sviataia Troitsa | Third rate | For Imperial Russian Navy. |
| 18 May | France | | Rochefort | Hélène | Charmante-class frigate | For French Navy. |
| 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. |
| 24 May | Russia | M. D. Portnov | Arkhangelsk | Arkhangel Rafail | Arkhangel Mikhail-class frigate | For Imperial Russian Navy. |
| 28 May | Russia | M. D. Portnov | Arkhangelsk | Garf Orlov | Aziia-class ship of the line | For Imperial Russian Navy. |
| 24 May | Russia | M. D. Portnov | Arkhangelsk | Pamiat Evstafii | Iaroslav-class ship of the line | For Imperial Russian Navy. |
| 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. |
| 29 June | Great Britain | Newland | Northam | Mount Royal | Brig | For private owner. |
| 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. |
| 16 July | Russia | Fursov | Taganrog | Ioann Zlatoust | Fifth rate | For Imperial Russian Navy. |
| 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. |
| 15 August | Great Britain | W. Richards | Hythe | Georgiana | Merchantman | For St. Barbe & Co. |
| 19 August | France | | Rochefort | Le Pyrrhus | Third rate | For French Navy. |
| 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. |
| 28 September | Portugal | | Lisbon | Serpente do Mar | Sixth rate | For Portuguese Navy. |
| 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. |
| 1 October | Denmark-Norway | Ernst Wilhelm Stibolt | Copenhagen | Glommen | Lougen-class brig | For Dano-Norwegian Navy. |
| 6 October | State of Brazil | | Bahia | Princesa Carlota | Fifth rate | For Portuguese Navy. |
| 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. |
| 22 December | Cuba | Landa Romero | Havana | Ceres | Fifth rate | For Spanish Navy. |
| 22 December | Cuba | | Havana | Infante Don Pelayo | Third rate | For Spanish Navy. |
| 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. |
| Unknown date | Great Britain | | Scarborough | Amphitrite | Merchantman | For private owner. |
| Unknown date | France | | Dunkerque | L'Anacréon | Privateer | For privateer. |
| Unknown date | United States | | New London, Connecticut | Argus | Sloop | For Revenue Cutter Service. |
| Unknown date | Great Britain | Nicholas Bools & William Good | Bridport | Brilliant | Cutter | For Nicholas Bools and William Good. |
| 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 | Nicholas Bools & William Good | Bridport | Cadiz Packet | Cutter | For private owner. |
| 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. |
| Unknown date | Great Britain | Nicholas Bools | Bridport | Grand Falconer | Cutter | For Duke of St Albans. |
| Unknown date | Kingdom of Sicily | Antonion Imbert | Castellamare del Golfo | Guiscard | Third rate | For Royal Sicilian Navy. |
| 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 | Nicholas Bools | Bridport | Rambler | Sloop | For Nicholas Bools. |
| 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. |
| 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. |