The country's population in the year to March increased by 316,000 people, according to the Australian Bureau of Statistics.
Net overseas migration was the biggest contributor to population growth, adding 173,100 people to the overall number.
Natural increase contributed 45 per cent of the total population growth consisting of 298,400 births (a 3 per cent fall on the previous year) and 155,500 deaths (a 4 per cent rise on the previous year).
Victoria experienced the fastest population growth rate in the country, adding 97,500 people or 1.7 per cent.
The Northern Territory recorded the lowest growth rate at 0.2 per cent.
"This is 80 per cent lower than that of March 2014".
Denise Carlton from the ABS said the numbers are the Northern Territory's lowest growth rate in 11 years.
"This is 80 per cent lower than that of March 2014," she said. "Net interstate migration losses were the greatest contributor to this slower growth, with the [Northern] Territory recording its largest ever interstate migration loss in the year to March 2015."
