6 January – First aircraft crash in Australia, between Mount Druitt and Rooty Hill.[1][2]
18 January – Tramway Employees Association members are dismissed for wearing union badges to work—the ensuing protest marks the beginning of the 1912 Brisbane general strike.[3]
4 February – Police officers and special constables attack protesters and strikers at Market Square in Brisbane during the 1912 Brisbane general strike. The day becomes known as "Baton Friday" and later, "Black Friday".[3]
20 or 21 March – The SS Koombana sinks off Western Australia during a cyclone, killing around 150 people.[4]
24 April – The NSW government grants 43 acres (17 ha) of land for the construction of a zoological garden, later known as Taronga Park.[6]
30 May – The light cruiser HMAS Melbourne is launched in England.[7]
15 July – The first branches of the Commonwealth Bank open in Melbourne and country Victoria. The Prime Minister, Andrew Fisher, is the bank's first account holder and depositor.[8]
10 October – The Maternity Allowance Act 1912 is passed, granting a "Baby Bonus" of five pounds to the mother of every child born in Australia (indigenous mothers and other non-citizens are excluded).[9]
5 May to 27 July – Australia sends women to the Olympic Games, the 1912 Summer Olympics in Stockholm, for the first time. Australasia won 2 gold, 2 silver and 3 bronze medals. Fanny Durack won the 100 metres freestyle. Australasia won the men's 4 × 200 m freestyle relay.