The following lists events that happened during 1915 in Australia.

• Monarch – George V
• Governor-General – Ronald Munro-Ferguson
• Prime Minister – Andrew Fisher (until 27 October), then Billy Hughes
• Chief Justice – Samuel Griffith

• 25 April – The Anzac tradition begins during World War I with a landing at Gallipoli on the Turkish coast.
• 30 April – Australian submarine AE2 sunk in Sea of Marmara.
• 6 June – The BHP Newcastle Steelworks opens in Newcastle, New South Wales.
• 19 July – Albert Jacka becomes the first Australian to win the Victoria Cross during World War I.
• 9 August – Alexander Burton died at Lone Pine, Gallipoli, Turkey. He was awarded the Victoria Cross.
• 24 August – The town of Holbrook was renamed from Germanton.
• 10 October – Twenty six men left Gilgandra on the Cooee March; the first of the World War I Snowball marches. At each town on the route they shouted "cooee" to attract recruits; the march arrived in Sydney on 12 November with 263 recruits.
• 27 October – Billy Hughes becomes the seventh Prime Minister of Australia and the first to serve consecutive terms in office.
• 20 December – Completion of Anzac evacuation from Gallipoli before dawn.
• Full date unknown:
  • Zaara Street Power Station is commissioned in Newcastle, New South Wales.^[1]

• 10 December – Father and son scientists William Henry Bragg and William Lawrence Bragg win the Nobel Prize in Physics.

• Patrobas wins the Melbourne Cup
• 1914/15 the Sheffield Shield was won by Victoria; after this season it was not contested due to the war.
• The 1915 NSWRFL Premiership is won by Balmain.

• 6 February – Donald Friend (died 1989), artist, writer and diarist
• 2 March – John Wear Burton (died 2010), public servant and diplomat
• 3 March – Manning Clark (died 1991), historian
• 6 March – Mary Ward (died 2021), actress
• 22 March – Charlotte Anderson (died 2002), professor of paediatrics
• 9 April – Bob Quinn (died 2008), SANFL footballer (Port Adelaide)
• 30 May – Michael Thwaites (died 2005), poet, academic and intelligence officer
• 31 May – Judith Wright (died 2000), poet
• 3 June – Jim McClelland (died 1999), senator and government minister
• 20 June – Dick Reynolds (died 2002), VFL footballer (Essendon)
• 16 July – David Campbell (died 1979), poet
• 3 August – Arthur John Birch (died 1995), organic chemist
• 26 October – Lindsay Pryor (died 1998), botanist
• 2 November – May Campbell (died 1981), field hockey player
• 25 November – Ron Hamence (died 2010), cricketer
• 29 November – Bob Cotton (died 2006), senator and government minister
• 31 December – John Murray (died 2009), politician

• 11 January – James Wilkinson, Queensland politician (b. 1854)
• 11 March – Thomas Alexander Browne, author (born in the United Kingdom) (b. 1826)
• 4 April – Sir Francis Bathurst Suttor, New South Wales politician and pastoralist (b. 1839)
• 19 April – Thomas Playford II, 17th Premier of South Australia (born in the United Kingdom) (b. 1837)^[2]
• 25 April - William Henry Strahan, writer and soldier (b. 1869)
• 2 June – George Randell, Western Australian politician (born in the United Kingdom) (b. 1830)
• 25 June – Frederick Manson Bailey, botanist (born in the United Kingdom) (b. 1827)
• 28 June – Victor Trumper, cricketer (b. 1877)
• 18 July – George Marshall-Hall, composer and poet (born in the United Kingdom) (b. 1862)
• 2 August – Sir John Downer, 16th Premier of South Australia (b. 1843)
• 8 October – E. Phillips Fox, impressionist painter (b. 1865)
• 29 October – Richard Edwards, Queensland politician (born in the United Kingdom) (d. 1915)
• 20 November – Robert Barr Smith, businessman and philanthropist (born in the United Kingdom) (b. 1824)
• 4 December – George Richards, New South Wales politician (b. 1865)
• 21 December – Thomas Sergeant Hall, geologist and biologist (b. 1858)