AD 21

Millennium: 1st millennium
Centuries:
Decades:
Years:
AD 21 in various calendars
Gregorian calendarAD 21
XXI
Ab urbe condita774
Assyrian calendar4771
Balinese saka calendarN/A
Bengali calendar−572
Berber calendar971
Buddhist calendar565
Burmese calendar−617
Byzantine calendar5529–5530
Chinese calendar庚辰年 (Metal Dragon)
2718 or 2511
    — to —
辛巳年 (Metal Snake)
2719 or 2512
Coptic calendar−263 – −262
Discordian calendar1187
Ethiopian calendar13–14
Hebrew calendar3781–3782
Hindu calendars
 - Vikram Samvat77–78
 - Shaka SamvatN/A
 - Kali Yuga3121–3122
Holocene calendar10021
Iranian calendar601 BP – 600 BP
Islamic calendar619 BH – 618 BH
Javanese calendarN/A
Julian calendarAD 21
XXI
Korean calendar2354
Minguo calendar1891 before ROC
民前1891年
Nanakshahi calendar−1447
Seleucid era332/333 AG
Thai solar calendar563–564
Tibetan calendar阳金龙年
(male Iron-Dragon)
147 or −234 or −1006
    — to —
阴金蛇年
(female Iron-Snake)
148 or −233 or −1005

AD 21 (XXI) was a common year starting on Wednesday of the Julian calendar. At the time, it was known as the Year of the Consulship of Tiberius and Drusus (or, less frequently, year 774 Ab urbe condita). The denomination AD 21 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.