Queensland's population is set to hit five million people four years ahead of schedule.
A baby born on Tuesday will become the state's five-millionth resident, Premier Annastacia Palaszczuk told state parliament.
It comes 13 years after the state reached four million people, with the expectation then that the five-mill mark wouldn't happen until 2022.
There was a further belief that the population would hit six million people in 2040, but with the current growth rate of approximately 80,000 new residents per year that could happen 10 years earlier.
Queensland is growing at about 1.7 per cent, higher than the national average (1.4), with international migration and natural increases the chief contributors.
But high housing prices in Sydney and Melbourne were starting to make their mark on the state, according to University of Queensland demographer Elin Charles-Edwards.
"For a couple of years, we had a low level of interstate migration, but we've seen this upswing in the past year or so," she told AAP.
"There's a bit of speculation the house price differential is starting to bite, so it is attracting people up here because it's just that more cheaper."
Dr Charles-Edwards said the state was coping with growth but warned against being in a position where it was playing "catch up".
She said more public transport in the south-east epicentre of growth was needed.
"I think the notion of having a metro system in inner city Brisbane's critical," she said.
"In the southeast corner, further rail connections out to the south and western corridor are really critical.
"I actually think Queensland's doing pretty well. We haven't had quite the pressures we've seen in the southern capitals.
"But it is certainly something that needs continued and ongoing attention, particularly with transport as the urban expanse gets bigger."
Last week's federal budget included $300 million for the Brisbane Metro project.
Ms Palaszczuk welcomed the population milestone.
"We often host heads of government or heads of state ... we are about to welcome our five millionth Queenslander," Ms Palaszczuk said in parliament.
"Everything we do in this house, is for that five millionth Queenslander."