| Millennium: | 1st millennium |
|---|---|
| Centuries: | |
| Decades: | |
| Years: |
| 921 by topic |
|---|
| Leaders |
| Categories |
| Gregorian calendar | 921 CMXXI |
| Ab urbe condita | 1674 |
| Armenian calendar | 370 ԹՎ ՅՀ |
| Assyrian calendar | 5671 |
| Balinese saka calendar | 842–843 |
| Bengali calendar | 328 |
| Berber calendar | 1871 |
| Buddhist calendar | 1465 |
| Burmese calendar | 283 |
| Byzantine calendar | 6429–6430 |
| Chinese calendar | 庚辰年 (Metal Dragon) 3618 or 3411 — to — 辛巳年 (Metal Snake) 3619 or 3412 |
| Coptic calendar | 637–638 |
| Discordian calendar | 2087 |
| Ethiopian calendar | 913–914 |
| Hebrew calendar | 4681–4682 |
| Hindu calendars | |
| - Vikram Samvat | 977–978 |
| - Shaka Samvat | 842–843 |
| - Kali Yuga | 4021–4022 |
| Holocene calendar | 10921 |
| Iranian calendar | 299–300 |
| Islamic calendar | 308–309 |
| Japanese calendar | Engi 21 (延喜２１年) |
| Javanese calendar | 820–821 |
| Julian calendar | 921 CMXXI |
| Korean calendar | 3254 |
| Minguo calendar | 991 before ROC 民前991年 |
| Nanakshahi calendar | −547 |
| Seleucid era | 1232/1233 AG |
| Thai solar calendar | 1463–1464 |
| Tibetan calendar | 阳金龙年 (male Iron-Dragon) 1047 or 666 or −106 — to — 阴金蛇年 (female Iron-Snake) 1048 or 667 or −105 |
Year 921 (CMXXI) was a common year starting on Monday (link will display the full calendar) of the Julian calendar.