A landmark study into the rights of Australian children has delivered a scathing assessment, accusing successive governments of failing to support the country's most vulnerable young people.

The report found state and federal governments have repeatedly breached the UN Convention on the Rights of the Child over the past 25 years and would continue to do so.

The study from the Australian Child Rights Taskforce, an organisation comprising more than 100 groups including UNICEF Australia and the National Children's and Youth Law Centre, highlighted the fact that one in six Australian children still lives in poverty despite two decades of economic growth.

A former chief justice of the Family Court of Australia and chairman of Children's Rights International, Alastair Nicholson, said Australian governments had repeatedly ignored the rights of young people, despite agreeing to the UN Convention in 1990.