1400
| Years | 
|---|
| Millennium | 
| 2nd millennium | 
| Centuries | 
| Decades | 
| Years | 
| 1400 by topic | 
|---|
| Leaders | 
| 
 | 
| Birth and death categories | 
| Births – Deaths | 
| Establishments and disestablishments categories | 
| Establishments – Disestablishments | 
| Art and literature | 
| 1400 in poetry | 
| Gregorian calendar | 1400 MCD | 
| Ab urbe condita | 2153 | 
| Armenian calendar | 849 ԹՎ ՊԽԹ | 
| Assyrian calendar | 6150 | 
| Balinese saka calendar | 1321–1322 | 
| Bengali calendar | 806–807 | 
| Berber calendar | 2350 | 
| English Regnal year | 1 Hen. 4 – 2 Hen. 4 | 
| Buddhist calendar | 1944 | 
| Burmese calendar | 762 | 
| Byzantine calendar | 6908–6909 | 
| Chinese calendar | 己卯年 (Earth Rabbit) 4097 or 3890 — to — 庚辰年 (Metal Dragon) 4098 or 3891 | 
| Coptic calendar | 1116–1117 | 
| Discordian calendar | 2566 | 
| Ethiopian calendar | 1392–1393 | 
| Hebrew calendar | 5160–5161 | 
| Hindu calendars | |
| - Vikram Samvat | 1456–1457 | 
| - Shaka Samvat | 1321–1322 | 
| - Kali Yuga | 4500–4501 | 
| Holocene calendar | 11400 | 
| Igbo calendar | 400–401 | 
| Iranian calendar | 778–779 | 
| Islamic calendar | 802–803 | 
| Japanese calendar | Ōei 7 (応永7年) | 
| Javanese calendar | 1314–1315 | 
| Julian calendar | 1400 MCD | 
| Korean calendar | 3733 | 
| Minguo calendar | 512 before ROC 民前512年 | 
| Nanakshahi calendar | −68 | 
| Thai solar calendar | 1942–1943 | 
| Tibetan calendar | 阴土兔年 (female Earth-Rabbit) 1526 or 1145 or 373 — to — 阳金龙年 (male Iron-Dragon) 1527 or 1146 or 374 | 
Year 1400 (MCD) was a leap year starting on Thursday of the Julian calendar. The year 1400 was not a leap year in the Proleptic Gregorian calendar, it was a common year starting on Wednesday.