 Australia 's population has quadrupled since the end of World War I , much of this increase from immigration . Following World War II and through to 2000 , almost 5 @.@ 9 million of the total population settled in the country as new immigrants , meaning that nearly two out of every seven Australians were born in another country . Most immigrants are skilled , but the immigration quota includes categories for family members and refugees . By 2050 , Australia 's population is currently projected to reach around 42 million . Nevertheless , its population density , 2 @.@ 8 inhabitants per square kilometre , remains among the lowest in the world . As such , Australians have more living space per person than the inhabitants of any other nation . 
