The 17-year-old boy's life support was switched off in hospital on Monday, about a week after the incident, Queensland Police said.
His death is the first fatality caused by the species in Australia since 2006, local media reported.
The Australian box jellyfish - so named for its shape - is considered to be the most venomous marine animal.
It has long barbed tentacles which are covered in pockets of venom. When injected into people or animals, it can lead to paralysis, cardiac arrest and death.