1023
| Years | 
|---|
| Millennium | 
| 2nd millennium | 
| Centuries | 
| Decades | 
| Years | 
| 1023 by topic | 
|---|
| Leaders | 
| 
 | 
| Birth and death categories | 
| Births – Deaths | 
| Establishments and disestablishments categories | 
| Establishments – Disestablishments | 
| Gregorian calendar | 1023 MXXIII | 
| Ab urbe condita | 1776 | 
| Armenian calendar | 472 ԹՎ ՆՀԲ | 
| Assyrian calendar | 5773 | 
| Balinese saka calendar | 944–945 | 
| Bengali calendar | 429–430 | 
| Berber calendar | 1973 | 
| English Regnal year | N/A | 
| Buddhist calendar | 1567 | 
| Burmese calendar | 385 | 
| Byzantine calendar | 6531–6532 | 
| Chinese calendar | 壬戌年 (Water Dog) 3720 or 3513 — to — 癸亥年 (Water Pig) 3721 or 3514 | 
| Coptic calendar | 739–740 | 
| Discordian calendar | 2189 | 
| Ethiopian calendar | 1015–1016 | 
| Hebrew calendar | 4783–4784 | 
| Hindu calendars | |
| - Vikram Samvat | 1079–1080 | 
| - Shaka Samvat | 944–945 | 
| - Kali Yuga | 4123–4124 | 
| Holocene calendar | 11023 | 
| Igbo calendar | 23–24 | 
| Iranian calendar | 401–402 | 
| Islamic calendar | 413–414 | 
| Japanese calendar | Jian 3 (治安3年) | 
| Javanese calendar | 925–926 | 
| Julian calendar | 1023 MXXIII | 
| Korean calendar | 3356 | 
| Minguo calendar | 889 before ROC 民前889年 | 
| Nanakshahi calendar | −445 | 
| Seleucid era | 1334/1335 AG | 
| Thai solar calendar | 1565–1566 | 
| Tibetan calendar | 阳水狗年 (male Water-Dog) 1149 or 768 or −4 — to — 阴水猪年 (female Water-Pig) 1150 or 769 or −3 | 
Year 1023 (MXXIII) was a common year starting on Tuesday of the Julian calendar.