Almost 850 young people are locked up in detention nationwide on any given night, with nine in 10 being boys, and the majority Indigenous children.
A report released by the Australian Institute of Health and Welfare on Friday, showed how many young people were in detention between June 2020 to June 2024.
There were 845 youths in custody in the June quarter this year, with 90 per cent of those being teen boys.
Six in 10 were Indigenous children, with 39 per cent non-Indigenous.
The rate of First Nations young people aged between 10 and 17 in detention increased.
Indigenous children were 27 times as likely as non-Indigenous young people to be in detention.
"First Nations people have a long history of over-representation in the youth and adult justice systems in Australia," the report reads.
"This over representation reflects a history of trauma, cultural dispossession, and forced displacement and assimilation that have affected them, their parents, families and communities."
The report found Indigenous people only make up 5.7 per of 10-17 year olds, but just under two thirds in youth detention are First Nations.
Although the number of people in detention has fluctuated, it has risen from 791 in the June quarter of 2020.
Of the total number of children in custody, 317 were in Queensland, followed by 240 in New South Wales, and 88 in Victoria.
Queensland had more young people locked up than Victoria, Western Australia, South Australia, Tasmania and the ACT combined.
A small number of young people aged between 10 and 13 were also in detention.
This figure also rose from 31 in the June quarter of 2020 to 38 in the June quarter of 2024.
The Northern Territory and ACT last year raised the minimum age of criminal responsibility to 12 from 10.
This means that young people aged 10 and 11 cannot be held criminally responsible for their conduct and were not supervised in the youth justice system during the 2023/2024 financial year.
In October the incoming NT government passed laws lowering the age of criminal responsibility back to 10.
The two main principles of the Australian youth justice system is that young people should be detained only as a last resort, and for the shortest appropriate period, the report says.
