| Millennium: | 1st millennium |
|---|---|
| Centuries: | 1st century BC – 1st century – 2nd century |
| Decades: | 60s 70s 80s – 90s – 100s 110s 120s |
| Years: | 88 89 90 – 91 – 92 93 94 |
| 91 by topic | |
| Politics | |
| State leaders – Sovereign states | |
| Birth and death categories | |
| Births – Deaths | |
| Establishment and disestablishment categories | |
| Establishments – Disestablishments | |
| Gregorian calendar | 91 XCI |
| Ab urbe condita | 844 |
| Armenian calendar | N/A |
| Bahá'í calendar | -1753 – -1752 |
| Bengali calendar | -502 |
| Berber calendar | 1041 |
| Buddhist calendar | 635 |
| Burmese calendar | -547 |
| Byzantine calendar | 5599 – 5600 |
| Chinese calendar | 庚寅年十一月廿三日 (2727/2787-11-23) — to —
辛卯年十二月初三日(2728/2788-12-3) |
| Coptic calendar | -193 – -192 |
| Ethiopian calendar | 83 – 84 |
| Hebrew calendar | 3851 – 3852 |
| Hindu calendars | |
| - Bikram Samwat | 147 – 148 |
| - Shaka Samvat | 13 – 14 |
| - Kali Yuga | 3192 – 3193 |
| Holocene calendar | 10091 |
| Iranian calendar | 531 BP – 530 BP |
| Islamic calendar | 547 BH – 546 BH |
| Japanese calendar | |
| Korean calendar | 2424 |
| Thai solar calendar | 634 |
Year 91 (XCI) was a common year starting on Saturday (link will display the full calendar) of the Julian calendar.