The attachment down under will see the 30-year-old royal go on patrol with an indigenous regiment's soldiers and train with the country's Special Forces, his Kensington Palace office has said today.
A spokesperson said the fourth in line to Britain's throne was "tremendously looking forward" to the experience.
It had been announced earlier that Harry will leave the British Army in June, after putting 10 years of service.
The Australian Defene Force said they want to provide Harry, who is known as Captain Wales in the Army, with an "authentic military experience".
On Monday, he will lay a wreath at the country's Tomb Of The Unknown Soldier in Canberra, during his only scheduled public appearance in Australia, before reporting for duty.
The prince will spend time at army barracks in Sydney, training on helicopter simulators before heading to Perth where he will train with the Special Air Service.
He will also spend time in Darwin where he will work with members of Norforce, the mostly indigenous unit that patrols northern Australia.
"Those experiences reinforced the huge admiration and respect he already had for Australian servicemen and women and has stoked his enthusiasm even more to build on those relationships in the next four weeks.
"On announcing his departure from the British Army earlier this month, Prince Harry said it had been a "tough decision" and that he was considering his future career options," the spokesperson added.