878
| Years | 
|---|
| Millennium | 
| 1st millennium | 
| Centuries | 
| Decades | 
| Years | 
| 878 by topic | 
|---|
| Leaders | 
| Categories | 
| 
 | 
| Gregorian calendar | 878 DCCCLXXVIII | 
| Ab urbe condita | 1631 | 
| Armenian calendar | 327 ԹՎ ՅԻԷ | 
| Assyrian calendar | 5628 | 
| Balinese saka calendar | 799–800 | 
| Bengali calendar | 284–285 | 
| Berber calendar | 1828 | 
| Buddhist calendar | 1422 | 
| Burmese calendar | 240 | 
| Byzantine calendar | 6386–6387 | 
| Chinese calendar | 丁酉年 (Fire Rooster) 3575 or 3368 — to — 戊戌年 (Earth Dog) 3576 or 3369 | 
| Coptic calendar | 594–595 | 
| Discordian calendar | 2044 | 
| Ethiopian calendar | 870–871 | 
| Hebrew calendar | 4638–4639 | 
| Hindu calendars | |
| - Vikram Samvat | 934–935 | 
| - Shaka Samvat | 799–800 | 
| - Kali Yuga | 3978–3979 | 
| Holocene calendar | 10878 | 
| Iranian calendar | 256–257 | 
| Islamic calendar | 264–265 | 
| Japanese calendar | Gangyō 2 (元慶2年) | 
| Javanese calendar | 776–777 | 
| Julian calendar | 878 DCCCLXXVIII | 
| Korean calendar | 3211 | 
| Minguo calendar | 1034 before ROC 民前1034年 | 
| Nanakshahi calendar | −590 | 
| Seleucid era | 1189/1190 AG | 
| Thai solar calendar | 1420–1421 | 
| Tibetan calendar | 阴火鸡年 (female Fire-Rooster) 1004 or 623 or −149 — to — 阳土狗年 (male Earth-Dog) 1005 or 624 or −148 | 
Year 878 (DCCCLXXVIII) was a common year starting on Wednesday of the Julian calendar.