1243 (MCCXLIII) was a common year starting on Thursday of the Julian calendar, the 1243rd year of the Common Era (CE) and Anno Domini (AD) designations, the 243rd year of the 2nd millennium, the 43rd year of the 13th century, and the 4th year of the 1240s decade. As of the start of 1243, the Gregorian calendar was 7 days ahead of the Julian calendar, which was the dominant calendar of the time.

Millennium: 2nd millennium
Centuries: 12th century13th century14th century
Decades: 1210s  1220s  1230s  – 1240s –  1250s  1260s  1270s
Years: 1240 1241 124212431244 1245 1246
1243 in other calendars
Gregorian calendar1243
MCCXLIII
Ab urbe condita1996
Armenian calendar692
ԹՎ ՈՂԲ
Assyrian calendar5993
Balinese saka calendar1164–1165
Bengali calendar650
Berber calendar2193
English Regnal year27 Hen. 3 – 28 Hen. 3
Buddhist calendar1787
Burmese calendar605
Byzantine calendar6751–6752
Chinese calendar壬寅(Water Tiger)
3939 or 3879
    — to —
癸卯年 (Water Rabbit)
3940 or 3880
Coptic calendar959–960
Discordian calendar2409
Ethiopian calendar1235–1236
Hebrew calendar5003–5004
Hindu calendars
 - Vikram Samvat1299–1300
 - Shaka Samvat1164–1165
 - Kali Yuga4343–4344
Holocene calendar11243
Igbo calendar243–244
Iranian calendar621–622
Islamic calendar640–641
Japanese calendarNinji 4 / Kangen 1
(寛元元年)
Javanese calendar1152–1153
Julian calendar1243
MCCXLIII
Korean calendar3576
Minguo calendar669 before ROC
民前669年
Nanakshahi calendar−225
Thai solar calendar1785–1786
Tibetan calendar阳水虎年
(male Water-Tiger)
1369 or 988 or 216
    — to —
阴水兔年
(female Water-Rabbit)
1370 or 989 or 217

Events change