| Millennium: | 1st millennium |
|---|---|
| Centuries: | 6th century – 7th century – 8th century |
| Decades: | 600s 610s 620s – 630s – 640s 650s 660s |
| Years: | 636 637 638 – 639 – 640 641 642 |
| 639 by topic | |
| Politics | |
| State leaders – Sovereign states | |
| Birth and death categories | |
| Births – Deaths | |
| Establishment and disestablishment categories | |
| Establishments – Disestablishments | |
| Gregorian calendar | 639 DCXXXIX |
| Ab urbe condita | 1392 |
| Armenian calendar | 88 ԹՎ ՁԸ |
| Assyrian calendar | 5389 |
| Bahá'í calendar | -1205–-1204 |
| Bengali calendar | 46 |
| Berber calendar | 1589 |
| English Regnal year | N/A |
| Buddhist calendar | 1183 |
| Burmese calendar | 1 |
| Byzantine calendar | 6147–6148 |
| Chinese calendar | 戊戌年十一月廿二日 (3275/3335-11-22) — to —
己亥年十二月初二日(3276/3336-12-2) |
| Coptic calendar | 355–356 |
| Ethiopian calendar | 631–632 |
| Hebrew calendar | 4399–4400 |
| Hindu calendars | |
| - Vikram Samvat | 695–696 |
| - Shaka Samvat | 561–562 |
| - Kali Yuga | 3740–3741 |
| Holocene calendar | 10639 |
| Iranian calendar | 17–18 |
| Islamic calendar | 17–19 |
| Japanese calendar | |
| Korean calendar | 2972 |
| Minguo calendar | 1273 before ROC 民前1273年 |
| Thai solar calendar | 1182 |
Year 639 (DCXXXIX) was a common year starting on Friday (link will display the full calendar) of the Julian calendar. The denomination 639 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.