Health modelling on the spread of coronavirus had initially predicted at least 30,000 Queenslanders would die if the virus was not contained.
Premier Annastacia Palaszczuk revealed the shocking figure while pleading with Queenslanders to adhere to social distancing rules.
"The initial modelling I was shown, if we didn't flatten the curve, it was over 30,000 Queenslanders could have lost their lives," she said.
"That keeps me up at night, thinking about how I can save people's lives.
"I don't like these restrictions as much as you don't. I can't see my family and friends, it's tough — but this is about saving people's lives."
Another nine cases of COVID-19 were confirmed in Queensland on Wednesday, taking the state's total tally to 943.
Five Queenslanders have died from the coronavirus and 11 people are being treated in intensive care.
But the Premier said the numbers of coronavirus cases had been trending downwards, which was a positive sign for the projected death rate.
"The reality is the virus is still here and we are still going to see tragic loss of life," she said.
"But we're going to get new modelling for the states and territories and we will see that [number] come down dramatically.
Restrictions to stay for six months
While the daily tallies of new cases have been falling dramatically over the past week, the Premier insisted restrictions must remain in place over coming weeks.
"There's no discussion at this present point in time about easing restrictions, let me make it very clear, " Ms Palaszczuk said.
"We've only just begun this journey. We are looking at six months here of these types of restrictions, in terms of the social distancing, the isolation, the quarantining, to flatten the curve.
"We have a good story in Queensland at the moment, so let's keep it up."
Earlier this week, the Government expanded the testing criteria to include anyone with respiratory symptoms around the Brisbane, Gold Coast and Cairns areas.
Queensland Health has said it is still too early to know whether the increased testing regime has identified further community transmission of the virus.
