1805
| Millennium: | 2nd millennium |
|---|---|
| Centuries: | 18th century – 19th century – 20th century |
| Decades: | 1770s 1780s 1790s – 1800s – 1810s 1820s 1830s |
| Years: | 1802 1803 1804 – 1805 – 1806 1807 1808 |
| Gregorian calendar | 1805 MDCCCV |
| French Republican calendar | 13–14 |
| Ab urbe condita | 2558 |
| Armenian calendar | 1254 ԹՎ ՌՄԾԴ |
| Assyrian calendar | 6555 |
| Balinese saka calendar | 1726–1727 |
| Bengali calendar | 1212 |
| Berber calendar | 2755 |
| British Regnal year | 45 Geo. 3 – 46 Geo. 3 |
| Buddhist calendar | 2349 |
| Burmese calendar | 1167 |
| Byzantine calendar | 7313–7314 |
| Chinese calendar | 甲子年 (Wood Rat) 4501 or 4441 — to — 乙丑年 (Wood Ox) 4502 or 4442 |
| Coptic calendar | 1521–1522 |
| Discordian calendar | 2971 |
| Ethiopian calendar | 1797–1798 |
| Hebrew calendar | 5565–5566 |
| Hindu calendars | |
| - Vikram Samvat | 1861–1862 |
| - Shaka Samvat | 1726–1727 |
| - Kali Yuga | 4905–4906 |
| Holocene calendar | 11805 |
| Igbo calendar | 805–806 |
| Iranian calendar | 1183–1184 |
| Islamic calendar | 1219–1220 |
| Japanese calendar | Bunka 2 (文化２年) |
| Javanese calendar | 1731–1732 |
| Julian calendar | Gregorian minus 12 days |
| Korean calendar | 4138 |
| Minguo calendar | 107 before ROC 民前107年 |
| Nanakshahi calendar | 337 |
| Thai solar calendar | 2347–2348 |
| Tibetan calendar | 阳木鼠年 (male Wood-Rat) 1931 or 1550 or 778 — to — 阴木牛年 (female Wood-Ox) 1932 or 1551 or 779 |
1805 (MDCCCV) was a common year starting on Tuesday in the Gregorian calendar and a common year starting on Sunday in the Julian calendar. The Gregorian calendar was 12 days ahead of the Julian calendar.