| Millennium: | 1st millennium |
|---|---|
| Centuries: | 8th century – 9th century – 10th century |
| Decades: | 800s 810s 820s – 830s – 840s 850s 860s |
| Years: | 828 829 830 – 831 – 832 833 834 |
| 831 by topic | |
| Politics | |
| State leaders – Sovereign states | |
| Birth and death categories | |
| Births – Deaths | |
| Establishment and disestablishment categories | |
| Establishments – Disestablishments | |
| Gregorian calendar | 831 DCCCXXXI |
| Ab urbe condita | 1584 |
| Armenian calendar | 280 ԹՎ ՄՁ |
| Assyrian calendar | 5581 |
| Bahá'í calendar | -1013–-1012 |
| Bengali calendar | 238 |
| Berber calendar | 1781 |
| English Regnal year | N/A |
| Buddhist calendar | 1375 |
| Burmese calendar | 193 |
| Byzantine calendar | 6339–6340 |
| Chinese calendar | 庚戌年十二月十四日 (3467/3527-12-14) — to —
辛亥年十一月廿四日(3468/3528-11-24) |
| Coptic calendar | 547–548 |
| Ethiopian calendar | 823–824 |
| Hebrew calendar | 4591–4592 |
| Hindu calendars | |
| - Vikram Samvat | 887–888 |
| - Shaka Samvat | 753–754 |
| - Kali Yuga | 3932–3933 |
| Holocene calendar | 10831 |
| Iranian calendar | 209–210 |
| Islamic calendar | 215–216 |
| Japanese calendar | |
| Korean calendar | 3164 |
| Minguo calendar | 1081 before ROC 民前1081年 |
| Thai solar calendar | 1374 |
Year 831 (DCCCXXXI) was a common year starting on Sunday (link will display the full calendar) of the Julian calendar.