August 31 is the 243rd day of the year. 122 days remain until the end of the year.
- 12 – Caligula, Roman emperor (d. 41)
- 161 – Commodus, Roman emperor (d. 192)
- 1168 – Zhang Zong, Chinese emperor (d. 1208)
- 1879 – Taishō, emperor of Japan (d. 1926)
- 1971 – Chris Tucker, American comedian and actor
- 1977 – Jeff Hardy, American wrestler and singer
- 1988 – Ember Moon, Professional Wrestler
- 1234 – Emperor Go-Horikawa of Japan (b. 1212)
- 1422 – Henry V of England (b. 1386)
- 1997 – Diana, Princess of Wales (b. 1961)
- 2013 – David Frost, English journalist and game show host (b. 1939)
- 1314 – King Haakon V of Norway moves the capital from Bergen to Oslo.
- 1422 – King Henry V of England dies of dysentery while in France. His son, Henry VI becomes King of England at the age of 9 months.
- 1864 – During the American Civil War, Union forces led by General William T. Sherman launch an assault on Atlanta.
- 1935 – In an attempt to stay out of the growing tensions concerning Germany and Japan, the United States passes the first of its Neutrality Acts.
- 1962 – Trinidad and Tobago becomes independent.
- 1991 – Kyrgyzstan declares its independence from the Soviet Union.
- 1997 – Diana, Princess of Wales, her companion Dodi Fayed and driver Henri Paul die in a car crash in Paris.
- 2005 – The 2005 Al-Aaimmah bridge stampede in Baghdad kills 953 people.
- 2006 – Edvard Munch’s famous painting The Scream, stolen on August 22, 2004, is recovered in a raid by Norwegian police.
- 2016 – Brazil’s President Dilma Rousseff is impeached and removed from office.
- Eat Outside Day
- Franchise Appreciation Day
- International Bacon Day
- Pony Express Day
- National Trail Mix Day
- Speak Kind Words Saturday