80-year-old Pillay was sworn in and reappointed as the Chairman of the Presidential Council of Advisers (CPA) for a period of four years by Singapore President Tony Tan Keng Yam.
Pillay, was also reappointed as a member of the CPA. Both appointments are for a further period of four years, with effect from January 2, 2015, the President's office said in a statement today.
As Chairman of the CPA, Pillay will exercise the functions of the President's office in the absence of President. If he is unavailable, the Speaker of Parliament would act as the head of state.
Pillay, who has served in a number of senior civil service positions, was first appointed to the CPA on January 2, 2001. He has served as Chairman of the CPA since September 2, 2005.
He is one of the pioneers who helped build the Singapore economy after its separation from Malaysia in 1965. He has served as Chairman of Singapore Airlines from 1972 until 1976.