The Queensland state capital is located on the northeast coast and has a population of more than two million residents. It will enter lockdown at 5pm on Monday local time (6am GMT). Four new locally transmitted Covid-19 cases were confirmed on Monday.
This takes the total linked to the UK variant to seven, after the first case was reported on Friday.
Residents will be required to stay at home unless they need to leave for essential work, healthcare, grocery shopping or exercise.
Pubs restaurants and cafes will be shut under rules of the snap lockdown – except for takeaway.
Annastacia Palaszczuk, Queensland state Premier, told reporters: “I know this is a really big call and I know it is really tough.
“We have Easter coming up, we have school holidays coming up but let’s do it now and let’s do it right.”