| Centuries: | 6th century · 7th century · 8th century |
| Decades: | 600s 610s 620s 630s 640s 650s 660s |
| Years: | 631 632 633 634 635 636 637 |
| 634 by topic | |
| Politics | |
| State leaders – Sovereign states | |
| Birth and death categories | |
| Births – Deaths | |
| Establishment and disestablishment categories | |
| Establishments – Disestablishments | |
| Gregorian calendar | 634 DCXXXIV |
| Ab urbe condita | 1387 |
| Armenian calendar | 83 ԹՎ ՁԳ |
| Bahá'í calendar | -1210 – -1209 |
| Bengali calendar | 41 |
| Berber calendar | 1584 |
| Buddhist calendar | 1178 |
| Burmese calendar | -4 |
| Byzantine calendar | 6142 – 6143 |
| Chinese calendar | 癸巳年十一月廿六日 (3270/3330-11-26) — to —
甲午年十二月初六日(3271/3331-12-6) |
| Coptic calendar | 350 – 351 |
| Ethiopian calendar | 626 – 627 |
| Hebrew calendar | 4394 – 4395 |
| Hindu calendars | |
| - Bikram Samwat | 690 – 691 |
| - Shaka Samvat | 556 – 557 |
| - Kali Yuga | 3735 – 3736 |
| Holocene calendar | 10634 |
| Iranian calendar | 12 – 13 |
| Islamic calendar | 12 – 13 |
| Japanese calendar | |
| Korean calendar | 2967 |
| Thai solar calendar | 1177 |