Back 1791 Abkhazian 1791 Afrikaans 1791 ALS 1791 እ.ኤ.አ. Amharic 1791 AN 1791 Arabic 1791 ARY 1791 ARZ 1791 AST 1791 AVK
| Millennium: | 2nd millennium |
|---|---|
| Centuries: | 17th century – 18th century – 19th century |
| Decades: | 1760s 1770s 1780s – 1790s – 1800s 1810s 1820s |
| Years: | 1788 1789 1790 – 1791 – 1792 1793 1794 |
| Gregorian calendar | 1791 MDCCXCI |
| Ab urbe condita | 2544 |
| Armenian calendar | 1240 ԹՎ ՌՄԽ |
| Assyrian calendar | 6541 |
| Balinese saka calendar | 1712–1713 |
| Bengali calendar | 1198 |
| Berber calendar | 2741 |
| British Regnal year | 31 Geo. 3 – 32 Geo. 3 |
| Buddhist calendar | 2335 |
| Burmese calendar | 1153 |
| Byzantine calendar | 7299–7300 |
| Chinese calendar | 庚戌年 (Metal Dog) 4487 or 4427 — to — 辛亥年 (Metal Pig) 4488 or 4428 |
| Coptic calendar | 1507–1508 |
| Discordian calendar | 2957 |
| Ethiopian calendar | 1783–1784 |
| Hebrew calendar | 5551–5552 |
| Hindu calendars | |
| - Vikram Samvat | 1847–1848 |
| - Shaka Samvat | 1712–1713 |
| - Kali Yuga | 4891–4892 |
| Holocene calendar | 11791 |
| Igbo calendar | 791–792 |
| Iranian calendar | 1169–1170 |
| Islamic calendar | 1205–1206 |
| Japanese calendar | Kansei 3 (寛政３年) |
| Javanese calendar | 1717–1718 |
| Julian calendar | Gregorian minus 11 days |
| Korean calendar | 4124 |
| Minguo calendar | 121 before ROC 民前121年 |
| Nanakshahi calendar | 323 |
| Thai solar calendar | 2333–2334 |
| Tibetan calendar | 阳金狗年 (male Iron-Dog) 1917 or 1536 or 764 — to — 阴金猪年 (female Iron-Pig) 1918 or 1537 or 765 |
1791 (MDCCXCI) was a common year starting on Saturday of the Gregorian calendar and a common year starting on Wednesday of the Julian calendar, the 1791st year of the Common Era (CE) and Anno Domini (AD) designations, the 791st year of the 2nd millennium, the 91st year of the 18th century, and the 2nd year of the 1790s decade. As of the start of 1791, the Gregorian calendar was 11 days ahead of the Julian calendar, which remained in localized use until 1923.