Portal:Australia/Anniversaries/September/September 3
- 1899 – Frank Macfarlane Burnet, biologist and Nobel Prize winner was born in Traralgon, Victoria.
- 1901 – the Flag of Australia and Australian Red Ensign are adopted by the Government of Australia as official flags, following a national design competition. The flag first flown from the Royal Exhibition Building, Melbourne.
- 1926 – The Canberra Times is first published.
- 1939 – Australia follows Britain and declares war on Germany.
- 1940 – The heavy cruiser HMAS Australia takes part in Operation Menace off Dakar.
- 1988 – Federal referendums on four-year parliamentary terms, recognition of local government and other issues are defeated.
- 1996 – Australian National Flag Day was proclaimed to commemorate the first flying of the Australian flag.