1621
| Millennium: | 2nd millennium |
|---|---|
| Centuries: | 16th century – 17th century – 18th century |
| Decades: | 1590s 1600s 1610s – 1620s – 1630s 1640s 1650s |
| Years: | 1618 1619 1620 – 1621 – 1622 1623 1624 |
| Gregorian calendar | 1621 MDCXXI |
| Ab urbe condita | 2374 |
| Armenian calendar | 1070 ԹՎ ՌՀ |
| Assyrian calendar | 6371 |
| Balinese saka calendar | 1542–1543 |
| Bengali calendar | 1028 |
| Berber calendar | 2571 |
| English Regnal year | 18 Ja. 1 – 19 Ja. 1 |
| Buddhist calendar | 2165 |
| Burmese calendar | 983 |
| Byzantine calendar | 7129–7130 |
| Chinese calendar | 庚申年 (Metal Monkey) 4317 or 4257 — to — 辛酉年 (Metal Rooster) 4318 or 4258 |
| Coptic calendar | 1337–1338 |
| Discordian calendar | 2787 |
| Ethiopian calendar | 1613–1614 |
| Hebrew calendar | 5381–5382 |
| Hindu calendars | |
| - Vikram Samvat | 1677–1678 |
| - Shaka Samvat | 1542–1543 |
| - Kali Yuga | 4721–4722 |
| Holocene calendar | 11621 |
| Igbo calendar | 621–622 |
| Iranian calendar | 999–1000 |
| Islamic calendar | 1030–1031 |
| Japanese calendar | Genna 7 (元和７年) |
| Javanese calendar | 1542–1543 |
| Julian calendar | Gregorian minus 10 days |
| Korean calendar | 3954 |
| Minguo calendar | 291 before ROC 民前291年 |
| Nanakshahi calendar | 153 |
| Thai solar calendar | 2163–2164 |
| Tibetan calendar | 阳金猴年 (male Iron-Monkey) 1747 or 1366 or 594 — to — 阴金鸡年 (female Iron-Rooster) 1748 or 1367 or 595 |
1621 (MDCXXI) was a common year starting on Friday of the Gregorian calendar and a common year starting on Monday of the Julian calendar, the 1621st year of the Common Era (CE) and Anno Domini (AD) designations, the 621st year of the 2nd millennium, the 21st year of the 17th century, and the 2nd year of the 1620s decade. As of the start of 1621, the Gregorian calendar was 10 days ahead of the Julian calendar, which remained in localized use until 1923.
Events
- February 9 – Gregory XV is elected pope.
- February 17 – Miles Standish is appointed as first commander of Plymouth Colony.
- March 16 – Samoset, a Wampanoag, visits the settlers of Plymouth Colony and greets them, "Welcome, Englishmen! My name is Samoset."
- March 22 – The Pilgrims of Plymouth Colony sign a peace treaty with Massasoit of the Wampanoags.
- April 5 – The Mayflower sets sail from Plymouth on a return trip to Great Britain.
- The Swedish city of Gothenburg is founded by Gustavus Adolphus
- Riga falls under rule of Sweden
- Willebrord Snell discovers the laws of refraction.