1918 in Australia was dominated by national participation in World War I. The Australian Corps, formed at the beginning of the year from the five divisions of the First Australian Imperial Force, played a significant role in the Allied victory.
21 March – John Bowser resigns as Premier of Victoria after his railway estimates bill is defeated in parliament. Harry Lawson forms a composite ministry of Liberal factions, including Bowser as Chief Secretary and Minister for Public Health.
25 April – Australian forces recapture Villers-Bretonneux from the German army helping to stop Operation Georgette.
31 May – John Monash takes command of the Australia Corps.
4 July – John Monash leads an attack on Hamel, regarded as one of the most prepared battles of the entire war.
8 August – The Battle of Amiens begins with British, Australian and Canadian troops participating in a successful offensive – General Erich Ludendorff described it as "the black day of the German Army".
12 August – King George V knights John Monash on the battlefield, the first British commander to be knighted in that way for 200 years.