Funds SA treasurer Tom Koutsantonis thanked Ms Nugent for her "magnificent" service to Funds SA during her tenure.
"Since being appointed [chair] in December 2000, Dr Nugent has steered Funds SA to achieve fantastic results for its investors, including the [South Australia's] public sector superannuation scheme," Mr Koutsantonis said.
Funds SA chief executive Jo Townsend said Ms Nugent has made an "invaluable contribution" to Funds SA over a sustained period of time.
"Her wisdom, insight, breadth of knowledge of the financial services sector, and the support she has provided to management and the board will be greatly missed," Ms Townsend said.
Ms Nugent is currently chair of Veda Group and the Australian Rail Track Corporation, as well as being a non-executive director of Origin Energy.
The South Australian state government will announce the appointment of a new Funds SA chair in the coming weeks.
