| Millennium: | 1st millennium |
|---|---|
| Centuries: | 6th century – 7th century – 8th century |
| Decades: | 640s 650s 660s – 670s – 680s 690s 700s |
| Years: | 675 676 677 – 678 – 679 680 681 |
| 678 by topic | |
| Politics | |
| State leaders – Sovereign states | |
| Birth and death categories | |
| Births – Deaths | |
| Establishment and disestablishment categories | |
| Establishments – Disestablishments | |
| Gregorian calendar | 678 DCLXXVIII |
| Ab urbe condita | 1431 |
| Armenian calendar | 127 ԹՎ ՃԻԷ |
| Bahá'í calendar | -1166 – -1165 |
| Bengali calendar | 85 |
| Berber calendar | 1628 |
| Buddhist calendar | 1222 |
| Burmese calendar | 40 |
| Byzantine calendar | 6186 – 6187 |
| Chinese calendar | 丁丑年十二月初三日 (3314/3374-12-3) — to —
戊寅年閏十一月十三日(3315/3375-intercalary 11-13) |
| Coptic calendar | 394 – 395 |
| Ethiopian calendar | 670 – 671 |
| Hebrew calendar | 4438 – 4439 |
| Hindu calendars | |
| - Bikram Samwat | 734 – 735 |
| - Shaka Samvat | 600 – 601 |
| - Kali Yuga | 3779 – 3780 |
| Holocene calendar | 10678 |
| Iranian calendar | 56 – 57 |
| Islamic calendar | 58 – 59 |
| Japanese calendar | |
| Korean calendar | 3011 |
| Thai solar calendar | 1221 |
678 was a year of the 7th century.