Ms Mackay, who is a principal of Sydney-based Quantum Financial, will join the APESB board from 1 July.
APESB chair and former federal Labor politician Nicola Roxon said the board welcomed Ms Mackay’s “range and depth of experience”.
“Claire brings with her a broad variety of skills and experience from the financial sector, as well as great energy and commitment,” Ms Roxon said.
Ms Mackay will replace Stuart Black who is retiring from the board at the end of June.