| 109681 | September 25 | Event | 1978 – PSA Flight 182, a Boeing 727, collides in mid-air with a Cessna 172 and crashes in San Diego, killing 144 people. |
| 109682 | September 25 | Event | 1981 – Belize joins the United Nations. |
| 109683 | September 25 | Event | 1983 – Maze Prison escape: Thirty-eight republican prisoners, armed with six handguns, hijack a prison meals lorry and smash their way out of the Maze prison. It is the largest prison escape since World War II and in British history. |
| 109684 | September 25 | Event | 1992 – NASA launches the Mars Observer, a $511 million probe to Mars, in the first U.S. mission to the planet in 17 years. Eleven months later, the probe would fail. |
| 109685 | September 25 | Event | 1996 – The last of the Magdalene asylums closes in Ireland. |
| 109686 | September 25 | Event | 2002 – The Vitim event, a possible bolide impact, occurs in Siberia, Russia. |
| 109687 | September 25 | Event | 2003 – A magnitude-8.0 earthquake strikes just offshore Hokkaidō, Japan. |
| 109688 | September 25 | Event | 2008 – China launches the spacecraft Shenzhou 7. |
| 109689 | September 25 | Event | 2009 – U.S. President Barack Obama, British Prime Minister Gordon Brown and French President Nicolas Sarkozy, in a joint TV appearance for a G-20 summit, accuse Iran of building a secret nuclear enrichment facility. |
| 109690 | September 25 | Birth | 1358 – Ashikaga Yoshimitsu, Japanese shogun (d. 1408) |
| 109691 | September 25 | Birth | 1403 – Louis III of Naples (d. 1434) |
| 109692 | September 25 | Birth | 1525 – Steven Borough, English explorer and navigator (d. 1584) |
| 109693 | September 25 | Birth | 1599 – Francesco Borromini, Swiss-Italian architect, designed the San Carlo alle Quattro Fontane and Sant'Agnese in Agone (d. 1667) |
| 109694 | September 25 | Birth | 1644 – Ole Rømer, Danish astronomer and instrument maker (d. 1710) |
| 109695 | September 25 | Birth | 1663 – Johann Nikolaus Hanff, German organist and composer (d. 1711) |
| 109696 | September 25 | Birth | 1683 – Jean-Philippe Rameau, French composer and theorist (d. 1764) |
| 109697 | September 25 | Birth | 1694 – Henry Pelham, English politician, Prime Minister of the United Kingdom (d. 1754) |
| 109698 | September 25 | Birth | 1711 – Qianlong Emperor of China (d. 1799) |
| 109699 | September 25 | Birth | 1738 – Nicholas Van Dyke, American lawyer and politician, 7th Governor of Delaware (d. 1789) |
| 109700 | September 25 | Birth | 1741 – Wenzel Pichl, Czech violinist, composer, and director (d. 1805) |
| 109701 | September 25 | Birth | 1744 – Frederick William II of Prussia (d. 1797) |
| 109702 | September 25 | Birth | 1758 – Josepha Barbara Auernhammer, Austrian pianist and composer (d. 1820) |
| 109703 | September 25 | Birth | 1764 – Fletcher Christian, English sailor (d. 1793) |
| 109704 | September 25 | Birth | 1766 – Armand-Emmanuel de Vignerot du Plessis, Duc de Richelieu, French general and politician, 2nd Prime Minister of France (d. 1822) |
| 109705 | September 25 | Birth | 1771 – Nikolay Raevsky, Russian general and politician (d. 1829) |
| 109706 | September 25 | Birth | 1773 – Agostino Bassi, Italian entomologist and author (d. 1856) |
| 109707 | September 25 | Birth | 1780 – Jason Fairbanks, American murderer (d. 1801) |
| 109708 | September 25 | Birth | 1782 – Charles Maturin, Irish author and playwright (d. 1824) |
| 109709 | September 25 | Birth | 1798 – Jean-Baptiste Élie de Beaumont, French geologist and engineer (d. 1874) |
| 109710 | September 25 | Birth | 1816 – Georg August Rudolph, German lawyer and politician, 3rd Mayor of Marburg (d. 1893) |