It was originally formed in 1915 during the First World War as part of the all-volunteer Australian Imperial Force (AIF) and saw service on the Western Front before being disbanded in 1919.

The 30th Battalion was originally raised for service as an Australian Imperial Force (AIF) unit during the First World War, as part of the 8th Brigade.

Formed in Australia in early August 1915, the battalion concentrated at Liverpool, New South Wales and drew most of its personnel from various parts of New South Wales, with a large contingent coming from Newcastle, although one company was formed from Victorian men who had volunteered to transfer from the Royal Australian Navy to serve in the infantry.

[4] The battalion's first major action came at Fromelles on 19 July 1916 where they were initially tasked to provide a supporting role, carrying ammunition to the assault troops, but they were later committed to the fighting as the situation deteriorated for the Australians.

When the Germans launched their Spring Offensive in early 1918, the 30th found itself in reserve for the majority of the time along with the rest of the 5th Division.

A series of advances followed as the Allies gained momentum, pushing their way through the Hindenburg Line defences around the Somme.

The 30th's final involvement in the fighting came in late September – early October 1918 when they took part in the Battle of St. Quentin Canal, which saw a joint Australian and American force breach the Hindenburg Line.

Following this the demobilisation process began and slowly the battalion's numbers were reduced as men were repatriated back to Australia in drafts.

[15][Note 2] While the Militia would provide a core of experienced personnel from which to recruit this force, their main role was to improve the nation's level of military preparedness by managing and administering the training of conscripts following the re-introduction of the compulsory training scheme in January 1940.

In early 1944, the units of the 8th Brigade were dispatched to New Guinea in support of the 9th Division which was taking part in the Huon Peninsula campaign.

Further operations saw the battalion advance along the coast and occupy Madang and Alexishafen, before returning to garrison duties in the Madang–Hansa Bay area following the completion of the campaign.

The following year, the Army introduced the Pentropic divisional structure and a wide-reaching re-organisation of the CMF structure was undertaken that saw a number of infantry battalions amalgamated or disbanded altogether as the regionally based single battalion regiments were replaced by six new multi-battalion State-based regiments.

[22] The Queen's and Regimental Colours of the 30th Battalion were laid up and are on display at St Stephen's Uniting Church, Sydney.