Private Richard Norden has been awarded the Victoria Cross for "conspicuous acts of gallantry" during the Battle of Fire Support Base Coral in 1968.
Private Norden, from Gundagai in regional NSW, was bestowed the honour for his efforts in running under heavy enemy fire to rescue his section commander, who had been wounded after their platoon was ambushed by North Vietnamese soldiers.
The Victoria Cross of Australia is the nation's highest military honour. (Mark Graham/AAP PHOTOS)
The 19-year-old then dragged the wounded section commander to safety and went back again for a forward scout, killing a North Vietnamese soldier who had been using the scout as a shield.
While the forward scout died, Private Norden went back a third time to collect grenades and clear the area to allow the body to be recovered.
Private Norden survived the war but died in a traffic accident while on duty serving in the ACT police in 1972. He was just 24.
Governor-General Sam Mostyn said Private Norden displayed extraordinary bravery.
"The Victoria Cross for Australia is Australia's highest military honour," she said. "The awarding of it speaks to Private Norden's courage and selflessness in the heat of battle, his ongoing legacy and the bravery of generations of our service personnel."
"This is a historic day for Australia and the Australian Defence Force and a significant day for Private Norden's loved ones."
Australian Governor-General Sam Mostyn honoured the late Private Richard Norden for his bravery. (Lukas Coch/AAP PHOTOS)
The Victoria Cross was awarded on Remembrance Day, 106 years to the day since the guns fell silent in World War I.
Arrangements for an investiture ceremony are under way.
The family of Private Norden said in a statement "we are honoured that His Majesty has approved the Victoria Cross for Australia for Richard, recognising his gallantry actions whilst serving in Vietnam".
Prime Minister Anthony Albanese said the actions of Private Norden were more than worthy of the Victoria Cross.
"Such was his courage that the enemy soldiers abandoned their positions and, as a result, many more Australian lives were saved," he said.
"Today, in honouring Richard Norden and all he fought for, Australia also honours all those who fought for him. His fellow veterans, those who served alongside him and those who took up his cause when they learned of his story, everyone who kept alive the memory of his valour."