Australia’s population has hit the magic 23 million for the first time, with the Australian Bureau of Statistics’ Population Clock striking 23 million at 9:57pm on 23 April.

The Director of ABS Demography, Bjorn Jarvis, said the ABS Population Clock gives an indication of what the population is estimated to be, based on a 12 month projection.

"I know I'll be watching the clock eagerly as we make our way towards 23 million this evening," Mr Jarvis said.

"The 23rd millionth person could be a new born baby, but could equally be a person coming to work in Australia or a returning backpacker who has been away for more than a year." 

Net overseas migration accounted for 60 per cent of Australia's total growth, with the remaining 40 per cent due to natural increase for the year ending 30 September 2012, suggesting it is less likely to be a new born baby. 

"This is the highest annual increase in net overseas migration in almost five years," Mr Jarvis said.

Since reaching 20 million in late 2003, there has been around three years between each million person increase, with the population reaching 21 million in 2007 and 22 million in 2010.