| 70771 | June 21 | Event | 1964 – Three civil rights workers, Andrew Goodman, James Chaney and Mickey Schwerner, are murdered in Neshoba County, Mississippi, United States, by members of the Ku Klux Klan. |
| 70772 | June 21 | Event | 1970 – Penn Central declares Section 77 bankruptcy, largest ever US corporate bankruptcy up to this date. |
| 70773 | June 21 | Event | 1973 – In handing down the decision in Miller v. California 413 US 15, the Supreme Court of the United States establishes the Miller test for obscenity in U.S. law. |
| 70774 | June 21 | Event | 1977 – Bülent Ecevit, of the CHP forms the new government of Turkey. |
| 70775 | June 21 | Event | 1982 – John Hinckley is found not guilty by reason of insanity for the attempted assassination of U.S. President Ronald Reagan. |
| 70776 | June 21 | Event | 2000 – Section 28 (of the Local Government Act 1988), outlawing the 'promotion' of homosexuality in the United Kingdom, is repealed in Scotland with a 99 to 17 vote. |
| 70777 | June 21 | Event | 2001 – A federal grand jury in Alexandria, Virginia, indicts 13 Saudis and a Lebanese in the 1996 bombing of the Khobar Towers in Saudi Arabia that killed 19 American servicemen. |
| 70778 | June 21 | Event | 2004 – SpaceShipOne becomes the first privately funded spaceplane to achieve spaceflight. |
| 70779 | June 21 | Event | 2005 – Edgar Ray Killen, who had previously been acquitted for the murders of James Chaney, Andrew Goodman, and Mickey Schwerner, is convicted of manslaughter 41 years afterwards (the case had been reopened in 2004). |
| 70780 | June 21 | Event | 2006 – Pluto's newly discovered moons are officially named Nix and Hydra. |
| 70781 | June 21 | Event | 2009 – Greenland assumes self-rule. |
| 70782 | June 21 | Event | 2012 – A boat carrying more than 200 refugees capsized in the Indian Ocean between the Indonesian island of Java and Christmas Island, killing 17 people and leaving 70 other missing. |
| 70783 | June 21 | Event | 2013 – A suicide bomber kills 15 and injures 20 in a Shi'ite mosque in the northwestern Pakistani city of Peshawar. |
| 70784 | June 21 | Birth | 1002 – Pope Leo IX (d. 1054) |
| 70785 | June 21 | Birth | 1226 – Bolesław V the Chaste of Poland (d. 1279) |
| 70786 | June 21 | Birth | 1528 – Maria of Austria, Holy Roman Empress (d. 1603) |
| 70787 | June 21 | Birth | 1535 – Leonhard Rauwolf, German physician and botanist (d. 1596) |
| 70788 | June 21 | Birth | 1639 – Increase Mather, American minister and author (d. 1723) |
| 70789 | June 21 | Birth | 1646 – Maria Francisca of Savoy (d. 1683) |
| 70790 | June 21 | Birth | 1676 – Anthony Collins, English philosopher and author (d. 1729) |
| 70791 | June 21 | Birth | 1703 – Joseph Lieutaud, French physician and anatomist (d. 1780) |
| 70792 | June 21 | Birth | 1706 – John Dollond, English optician and astronomer (d. 1761) |
| 70793 | June 21 | Birth | 1710 – James Short, Scottish-English mathematician and optician (d. 1768) |
| 70794 | June 21 | Birth | 1712 – Luc Urbain de Bouëxic, comte de Guichen, French admiral (d. 1790) |
| 70795 | June 21 | Birth | 1730 – Motoori Norinaga, Japanese poet and scholar (d. 1801) |
| 70796 | June 21 | Birth | 1732 – Johann Christoph Friedrich Bach, German pianist and composer (d. 1791) |
| 70797 | June 21 | Birth | 1736 – Enoch Poor, American general (d. 1780) |
| 70798 | June 21 | Birth | 1738 – Gottlieb Christoph Harless, German linguist and scholar (d. 1815) |
| 70799 | June 21 | Birth | 1741 – Prince Benedetto, Duke of Chablais (d. 1808) |
| 70800 | June 21 | Birth | 1750 – Pierre-Nicolas Beauvallet, French sculptor and illustrator (d. 1818) |