Millennium: 2nd millennium
1991 in various calendars
Gregorian calendar1991
Ab urbe condita2744
Armenian calendar1440
Assyrian calendar6741
Bahá'í calendar147–148
Balinese saka calendar1912–1913
Bengali calendar1398
Berber calendar2941
British Regnal year39 Eliz. 2 – 40 Eliz. 2
Buddhist calendar2535
Burmese calendar1353
Byzantine calendar7499–7500
Chinese calendar庚午(Metal Horse)
4687 or 4627
    — to —
辛未年 (Metal Goat)
4688 or 4628
Coptic calendar1707–1708
Discordian calendar3157
Ethiopian calendar1983–1984
Hebrew calendar5751–5752
Hindu calendars
 - Vikram Samvat2047–2048
 - Shaka Samvat1912–1913
 - Kali Yuga5091–5092
Holocene calendar11991
Igbo calendar991–992
Iranian calendar1369–1370
Islamic calendar1411–1412
Japanese calendarHeisei 3
Javanese calendar1923–1924
Juche calendar80
Julian calendarGregorian minus 13 days
Korean calendar4324
Minguo calendarROC 80
Nanakshahi calendar523
Thai solar calendar2534
Tibetan calendar阳金马年
(male Iron-Horse)
2117 or 1736 or 964
    — to —
(female Iron-Goat)
2118 or 1737 or 965
Unix time662688000 – 694223999

1991 (MCMXCI) was a common year starting on Tuesday of the Gregorian calendar, the 1991st year of the Common Era (CE) and Anno Domini (AD) designations, the 991st year of the 2nd millennium, the 91st year of the 20th century, and the 2nd year of the 1990s decade.

It was the final year of the Cold War that had begun in 1947. During the year, the Union of Soviet Socialist Republics fell, leaving fifteen sovereign republics and the CIS in its place. In July 1991, India abandoned its policies of socialism and autarky and began extensive neoliberal changes to its economy. This increased GDP, but also increased economic inequality over the next two decades.[1] A U.N.-authorized coalition force from 34 nations fought against Iraq, which had invaded and annexed Kuwait in the previous year, 1990. The conflict would be called the Gulf War and would mark the beginning of a since-constant American military presence in the Middle East. The clash between Serbia and the other Yugoslav republics would lead into the beginning of the Yugoslav Wars, which ran through the rest of the decade.

The Japanese asset price bubble burst this year, leading to the Lost Years and a permanently stagnated (though still prosperous) Japanese economy.