Portal:Australia/Anniversaries/October/October 27
- 1897 – St Patrick's Cathedral, Melbourne is consecrated.
- 1900 – Notorious murderer Jimmy Governor is apprehended near Wingham, New South Wales.
- 1915 – Billy Hughes becomes the seventh Prime Minister of Australia and the first to serve consecutive terms in office.
- 1927 – Melbourne gangster Squizzy Taylor is killed in a shootout.
- 1953 – British nuclear test Totem 2 is detonated at Emu Field, South Australia.
- 1964 – Mark Taylor, Australian cricket player and Test captain from 1994–1999, is born in Leeton, New South Wales.
- 1980 – The Great Barrier Reef is listed as a World Heritage Site.
- 1990 – Northern Territory elections return Country Liberal Party government of Marshall Perron to power.
- 2002 – Terrorist group Jemaah Islamiah (JI) is banned by the Attorney-General.