South Australia's independent advocate for children and young people will step down after almost four years in the role, having been an outspoken defender of some of the state's most vulnerable children.

Shona Reid, South Australia's Guardian for Children and Young People, will leave the role in August to become chief executive of Aboriginal Family Support Services.

In a statement, Ms Reid said serving the state's children and young people had been the "greatest honour of my career". She argued every decision she made had been guided by the question: "What would children and young people want us to do?"

"I am profoundly grateful to the hundreds of children and young people who trusted me with their journey," she said. "Their courage, honesty and resilience have shaped every piece of advocacy, every report and every recommendation made by this Office. They have been my greatest teachers."

During her tenure, Ms Reid was a vocal advocate for reforming youth justice and repeatedly held the government to account over the treatment of children in out-of-home care (OOHC) and youth detention. Appointed in 2022, she argued she had focused on strengthening the Office's independence, advocacy and oversight of children and young people in out-of-home care and youth detention.

The Office secured additional government funding in 2024 and expanded its advocacy services, increased visits to residential care and youth detention facilities, and improved access to independent support for children and young people.

Furthermore, the Office broadened its advocacy through inquiries, inspections, parliamentary reporting, submissions and policy reform work, placing an emphasis on proactive oversight and putting the voices of children and young people front and centre in reports and recommendations.

Throughout her time as Guardian, she was an outspoken critic of the treatment of children in care and detention, often taking to the media to call for change.

In an interview with this masthead last year, the Eastern Arrernte woman said many children in care continued to feel unsafe or were exposed to violence, despite having been removed from harmful home environments.

"Do we care less because they're in youth detention and we're allowing this to happen?" she asked at the time. "Or is this just one of those wicked problems that we haven't yet been able to manage because their [children and young people's] behaviours — but also the way they interact with the world — is really complex, and we haven't figured it out."

She was also critical of the South Australian government's opposition to raising the age of criminal responsibility and accused the Attorney-General of ignoring reports prepared by her office.

In reflecting on her tenure, Ms Reid said the Office had become more visible, accessible and proactive in promoting the lived experiences of children and young people. She said it wasn't any one report or reform that gave her the most pride. Rather, "It is knowing that independent oversight is stronger today than when I commenced."

"I hope the legacy we leave is one where children know there is an independent Office that will always listen, always advocate and always stand beside them," she said.