Raised on 20 December 1941 under the command of Brigadier Thomas Louch[1] for service during World War II, the 29th Brigade was formed as part of the Militia, Australia's part-time military force.

The brigade's headquarters opened in January 1942 at Ascot, Queensland, and the formation was initially tasked with undertaking defensive duties in response to concerns about a possible invasion from the Japanese.

[4] During the Battle of Coral Sea, when the threat of invasion seemed imminent, the brigade was moved to the coast, issued ammunition for the first time and stood-to in preparation for a Japanese landing.

In the event, this invasion did not occur and the brigade was stood down, returning to more mundane garrison duties,[5] before moving to Mount Spec, to undertake jungle training in preparation for overseas service.

[4][7][3] The brigade was later committed to the Salamaua–Lae campaign in August 1943, taking part in the final stages of the fighting around Mount Tambu, in support of the advance on Salamaua.

[3] Throughout late August and early September, the 15th Battalion launched an attack around the right flank of the US 162nd Infantry Regiment, against a Japanese position along the Lokanu and Scout Ridges.

The brigade's efforts to secure a crossing over the Silibai River were frustrated by determined Japanese defence which held them up between 3 and 10 July, when the Australians successfully pushed their way across.