Tasmania's Commissioner for Children and Young People Mark Morrissey has stepped down and will leave the role in September.
Mr Morrissey took up the position in late-2014 and won't see out an expected five-year term.
He released a report in January with seven recommendations aimed at improving the lives of children in out-of-home care.
"I would encourage all sides of politics to stay the course with the current set of reforms to the child protection and out of home care systems," Mr Morrissey said, indicating he was planning to transition to part-time work.
His resignation comes amid ongoing criticism of the state government's handling of child protection matters. including the Safe Pathways saga in which the care provider was accused of neglecting children.
The state's Labor opposition has labelled Mr Morrissey's timing as "suspicious".
"The government has been accused of putting politics ahead of child protection, now the independent voice in the sector has resigned," Labor MP Josh Willie said.
Minister for Human Services Jacquie Petrusma praised Mr Morrissey for his significant contribution to promoting the rights and wellbeing of children.
The government will try to fill the role as soon as possible.