1921 in Australia

Incumbents

• Monarch – George V
• Governor-General – Henry Forster
• Prime Minister – Billy Hughes
• Chief Justice – Adrian Knox

  State premiers

• Premier of New South Wales – John Storey, then James Dooley, then George Fuller, then James Dooley
• Premier of Queensland – Ted Theodore
• Premier of South Australia – Henry Barwell
• Premier of Tasmania – Walter Lee
• Premier of Victoria – Harry Lawson
• Premier of Western Australia – James Mitchell

  State governors

• Governor of New South Wales – Sir Walter Davidson
• Governor of Queensland – Sir Matthew Nathan
• Governor of South Australia – Sir William Weigall
• Governor of Tasmania – Sir William Allardyce
• Governor of Victoria – George Rous, 3rd Earl of Stradbroke
• Governor of Western Australia – Sir Francis Newdegate

  Events

• March – Group Settlement Scheme begins at Manjimup, Western Australia.
• 7 March – The Commonwealth Department of Health is formed.
• 12 March – Edith Cowan becomes the first female parliamentarian in Australia, when she is elected to the Western Australian Legislative Council.
• 22 March – New South Wales MP Percy Brookfield is shot and killed when he tackles a crazed gunman at the train station in Riverton, South Australia.
• 31 March – The Royal Australian Air Force is established.
• 9 May – Australia assumes responsibility for administration of the Territory of New Guinea, following a League of Nations mandate divesting Germany of its colonies as required by the Treaty of Versailles.
• 30 August – A general election is held in Victoria. Harry Lawson of the Nationalist Party is returned as premier, although in a minority government.
• 26 October – The first group of Barnardo's Boys arrived in Sydney.
• 3 November – Federal MP Walter Marks told the House of Representatives that Armageddon would occur in 1934.
• 13 November – The cartoon character Ginger Meggs makes his first appearance, in a Sunday Sun comic strip "Us Fellers" drawn by cartoonist Jimmy Bancks.
• 30 December – Twelve-year-old Alma Tirtschke is raped and murdered in Melbourne, in what becomes known as the Gun Alley Murder.
• 31 December – Walter Burley Griffin is removed as director of construction for Canberra after disagreements over his supervisory role.

  Arts and literature

• William McInnes wins the inaugural Archibald Prize for portraiture
• Droving into the light – Hans Heysen
• Weighing the fleece – George W Lambert
• The White Glove – George W Lambert

  Film

Sport

• Sister Olive wins the Melbourne Cup
• New South Wales wins the Sheffield Shield
• In Test Cricket, Australia defeated England in The Ashes series
• A Le Fevre wins the Australian Open Championship in golf
• The 1921 VFL seasonThe Premiership is won by Richmond 5.6.36 to Carlton 4.8.32. Attendance 43,122 at the MCG.
• The 1921 NSWRFL season sees the introduction of the St. George club. The Premiership is won by North Sydney.

  Births

• 3 January
• *Bob Dawson, Australian rules footballer
• *Vasey Houghton, politician and conservationist
• 9 January – Bunney Brooke, actor
• 3 February – John Millett, poet
• 16 February – Bill Knott, NSW politician
• 21 February – Rupert Myers, metallurgist
• 4 March – Walter Campbell, Governor of Queensland
• 12 March – Norm Foster, politician
• 28 April – Robert Furlonger, diplomat and public servant
• 29 March – Sam Loxton, cricketer
• 1 April – Harold James Frith, ornithologist
• 13 April – Max Harris, writer
• 13 May – George Petersen, Labor politician
• 26 May – Norman Hetherington, artist, puppeteer
• 28 May – Tom Uren, Labor politician
• 3 June – Forbes Carlile, swimming coach and Olympic pentathlete
• 7 June – Myrtle Edwards, cricketer and softball player
• 19 June – Patricia Wrightson, children's author
• 1 July – Teddy Long, Australian rules footballer
• 22 July – Ronald N. Bracewell, physicist and radio astronomer
• 31 July – John Makepeace Bennett, computer scientist
• 9 August – Catherine Pym, fencer
• 20 August – Jack Wilson, cricketer
• 21 November – Betty Wilson, cricketer
• 24 November – Allan Ashbolt, journalist
• 26 December – Donald Horne, journalist and writer

  Deaths

• 14 January – Edward Hamersley, WA politician
• 27 January – Maurice Vincent Buckley, soldier and Victoria Cross recipient
• 14 March – Gustave Barnes, artist
• 21 May – Oswald Watt, aviator
• 6 June – William Mark Forster, philanthropist
• 18 June – G. H. Gibson, writer and satirist
• 2 July – Edwin Evans, cricketer
• 12 July – Harry Hawker, aviation pioneer
• 26 July – Howard Vernon, actor
• 1 August – T. J. Ryan, Premier of Queensland
• 23 August – Frank Hann, explorer
• 13 September – James Hebblethwaite, poet
• 5 October – John Storey, Premier of New South Wales
• 30 October – James Murdoch, Scottish journalist
• 6 November – Robert Logan Jack, geologist
• 17 November – John McLaren, cricketer
• 27 November - Mary Grant Roberts, zoo owner
• 24 December – William Curran, cricketer