Oxfam has welcomed an Australian-first move to raise the criminal age of responsibility to 14.
The ACT is the first jurisdiction to move on raising the age from 10 to 14, keeping more children out of prison.
Current policies were not in the best interests of children and disproportionately harmed First Nations kids and their families, the non-profit said.
Oxfam's Jimi Peters called on all states and territories to raise the age.
"Raising the age is one action that Australian governments can take right now that will have an immediate and generational impact to end the over-incarceration of First Nations people," he said.
The ACT law, passed on Wednesday, raises the age from 10 to 12 and then to 14 from July 1, 2025.
Boosted services and the raised ages were steps that would help break cycles of disadvantage and divert children from crime and reoffending, ACT Attorney-General Shane Rattenbury said.
The establishment of a therapeutic support panel to work with children and boost support for those who engage in harmful behaviour will also help to improve lifelong outcomes, ACT Health Minister Rachel Stephen-Smith said.
"Moving away from the criminal justice system and towards a brighter future," she said.
The reforms were also welcomed by the ACT children and young people commissioner, the Youth Coalition of the ACT and the Office for ACT Aboriginal and Torres Strait Islander Children and Young People.