The age of criminal responsibility needs to lift to at least 14 years, the First Peoples' Assembly of Victoria says.
In an open letter posted on Thursday, the assembly's co-chair Aunty Geraldine Atkinson urged the government to listen to evidence children as young as 10 should not be in custody.
"We don't want another year to go by with more of our children getting caught in the quicksand of the criminal justice system," Aunty Geraldine said in the letter.
"We need reform, yesterday.
"I urge you to listen to First Peoples. Listen to your own conscience, which surely must tell you that children do not belong in prisons. And act now."
Premier Daniel Andrews on Monday said his government wanted a change to the age of criminality but it would only come through a consistent, national approach.
"There's a forum to do that and that's the standing committee of attorneys-general," the premier told reporters.
"Under (federal Attorney-General) Mark Dreyfus' chairmanship, there's a much greater chance of getting that done."
Aunty Geraldine will next week give evidence to the Yoorrook Justice Commission, Australia's first truth-telling inquiry.
The commission has been holding public hearings as Victoria embarks on a process towards a treaty or treaties with First Nations peoples.
During Thursday's public hearing, Aunty Charmaine Clarke detailed her story of being a survivor of the stolen generation.
She was only two-and-a-half years old when she and her siblings were taken from their parents in Melbourne.
She became a ward of the state and was sent to an institution in Ballarat, more than 100km west of Melbourne.
It was only when Aunty Charmaine was about six or seven she saw her parents again.
"It's burnt into my memory. I ran to them. We cried. I thought I was going home, but I wasn't," she told the commission.
Throughout her childhood and early teen years, Aunty Charmaine was made to live and spend time with white families.
She experienced physical, sexual and psychological abuse, before she ran away at the age of 14.
That was the year her 38-year-old father died from a heart attack and her hopes of being reunited as a family were dashed.
"My parents had a house. We started making plans to be a family. We saw the finishing line, but then Dad died and it never happened," Aunty Charmaine said.
Aunty Charmaine, 55, said she felt ashamed for many years because she was told her Aboriginality was a bad thing.
She urged the commission to consider changes to power imbalances between government and Indigenous people.
Aunty Charmaine told the inquiry traditional healers should become part of an allied health response so Aboriginal people are not unnecessarily prescribed medication.
She said when it comes to child protection, there need to be greater incentives for Indigenous families to become carers.
"It's not because they don't want to," Aunty Charmaine said.
"A lot of families are just really struggling, so it's a bigger ask."
Jacynta Krakouer from Monash University told the inquiry western perspectives on family were resulting in more Aboriginal children ending up in the child protection system.
Children were viewed as individuals under the Euro-centric approaches, while First Nations peoples see a child as belonging to a family, community and country.
Removing Aboriginal children and disconnecting them from their families would only create more harm for the child, regardless of their family environment, Dr Krakouer said.
