| Millennium: | 1st Millennium BC |
|---|---|
| Centuries: | 8th cent. BC – 7th cent. BC – 6th cent. BC |
| Decades: | 690s BC 680s BC 670s BC – 660s BC – 650s BC 640s BC 630s BC |
| Years: | 664 BC 663 BC 662 BC – 661 BC – 660 BC 659 BC 658 BC |
| Gregorian calendar | 661 DCLXI |
| Ab urbe condita | 1414 |
| Armenian calendar | 110 ԹՎ ՃԺ |
| Assyrian calendar | 5411 |
| Bengali calendar | 68 |
| Berber calendar | 1611 |
| Buddhist calendar | 1205 |
| Burmese calendar | 23 |
| Byzantine calendar | 6169–6170 |
| Chinese calendar | 庚申年 (Metal Monkey) 3357 or 3297 — to — 辛酉年 (Metal Rooster) 3358 or 3298 |
| Coptic calendar | 377–378 |
| Discordian calendar | 1827 |
| Ethiopian calendar | 653–654 |
| Hebrew calendar | 4421–4422 |
| Hindu calendars | |
| - Vikram Samvat | 717–718 |
| - Shaka Samvat | 582–583 |
| - Kali Yuga | 3761–3762 |
| Holocene calendar | 10661 |
| Iranian calendar | 39–40 |
| Islamic calendar | 40–41 |
| Japanese calendar | N/A |
| Javanese calendar | 552–553 |
| Julian calendar | 661 DCLXI |
| Korean calendar | 2994 |
| Minguo calendar | 1251 before ROC 民前1251年 |
| Nanakshahi calendar | −807 |
| Seleucid era | 972/973 AG |
| Thai solar calendar | 1203–1204 |
The year 661 BC