| Millennium: | 1st millennium |
|---|---|
| Centuries: | 1st century – 2nd century – 3rd century |
| Decades: | 90s 100s 110s – 120s – 130s 140s 150s |
| Years: | 120 121 122 – 123 – 124 125 126 |
| 123 by topic | |
| Politics | |
| State leaders – Sovereign states | |
| Birth and death categories | |
| Births – Deaths | |
| Establishment and disestablishment categories | |
| Establishments – Disestablishments | |
| Gregorian calendar | 123 CXXIII |
| Ab urbe condita | 876 |
| Armenian calendar | N/A |
| Assyrian calendar | 4873 |
| Bahá'í calendar | -1721–-1720 |
| Bengali calendar | -470 |
| Berber calendar | 1073 |
| English Regnal year | N/A |
| Buddhist calendar | 667 |
| Burmese calendar | -515 |
| Byzantine calendar | 5631–5632 |
| Chinese calendar | 壬戌年十一月十七日 (2759/2819-11-17) — to —
癸亥年十一月廿六日(2760/2820-11-26) |
| Coptic calendar | -161–-160 |
| Ethiopian calendar | 115–116 |
| Hebrew calendar | 3883–3884 |
| Hindu calendars | |
| - Vikram Samvat | 179–180 |
| - Shaka Samvat | 45–46 |
| - Kali Yuga | 3224–3225 |
| Holocene calendar | 10123 |
| Iranian calendar | 499 BP – 498 BP |
| Islamic calendar | 514 BH – 513 BH |
| Japanese calendar | |
| Korean calendar | 2456 |
| Minguo calendar | 1789 before ROC 民前1789年 |
| Thai solar calendar | 666 |
Year 123 (CXXIII) was a common year starting on Thursday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Paetinus and Apronianus (or, less frequently, year 876 Ab urbe condita). The denomination 123 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.