2021 CE
- Common Era
- 2021 CE
- Gregorian Calendar
- 2021 AD
- Holocene Calendar
- 12021 HE
- Japanese Calendar
- Heisei 33 (平成33年)
- Japanese Imperial Year
- Kōki 2681 (皇紀2681年)
- Chinese Sexagenary Cycle
- Yin Metal Ox (辛丑)
Milestones
- First human in space
- 60 years ago
- World War II ends
- 76 years ago
- Hindu-Arabic numerals introduced to Europe
- 819 years ago
- Mythical founding of Japan
- 2680 years ago
- Foundation of Rome
- 2773 years ago
- Beginning of Xia Dynasty in China
- 4121 years ago
- First Egyptian pyramid completed
- 4631 years ago
- End of the Paleolithic Period
- 12020 years ago