1123
| Years | 
|---|
| Millennium | 
| 2nd millennium | 
| Centuries | 
| Decades | 
| Years | 
| 1123 by topic | 
|---|
| Leaders | 
  | 
| Birth and death categories | 
| Births – Deaths | 
| Establishments and disestablishments categories | 
| Establishments – Disestablishments | 
| Art and literature | 
| 1123 in poetry | 
| Gregorian calendar | 1123 MCXXIII  | 
| Ab urbe condita | 1876 | 
| Armenian calendar | 572 ԹՎ ՇՀԲ  | 
| Assyrian calendar | 5873 | 
| Balinese saka calendar | 1044–1045 | 
| Bengali calendar | 529–530 | 
| Berber calendar | 2073 | 
| English Regnal year | 23 Hen. 1 – 24 Hen. 1 | 
| Buddhist calendar | 1667 | 
| Burmese calendar | 485 | 
| Byzantine calendar | 6631–6632 | 
| Chinese calendar | 壬寅年 (Water Tiger) 3820 or 3613 — to — 癸卯年 (Water Rabbit) 3821 or 3614  | 
| Coptic calendar | 839–840 | 
| Discordian calendar | 2289 | 
| Ethiopian calendar | 1115–1116 | 
| Hebrew calendar | 4883–4884 | 
| Hindu calendars | |
| - Vikram Samvat | 1179–1180 | 
| - Shaka Samvat | 1044–1045 | 
| - Kali Yuga | 4223–4224 | 
| Holocene calendar | 11123 | 
| Igbo calendar | 123–124 | 
| Iranian calendar | 501–502 | 
| Islamic calendar | 516–517 | 
| Japanese calendar | Hōan 4 (保安4年)  | 
| Javanese calendar | 1028–1029 | 
| Julian calendar | 1123 MCXXIII  | 
| Korean calendar | 3456 | 
| Minguo calendar | 789 before ROC 民前789年  | 
| Nanakshahi calendar | −345 | 
| Seleucid era | 1434/1435 AG | 
| Thai solar calendar | 1665–1666 | 
| Tibetan calendar | 阳水虎年 (male Water-Tiger) 1249 or 868 or 96 — to — 阴水兔年 (female Water-Rabbit) 1250 or 869 or 97  | 
Year 1123 (MCXXIII) was a common year starting on Monday of the Julian calendar.