President Tony Tan Keng Yam has re-appointed Mr J Y Pillay as chairman as well as a member of the Council of Presidential Advisers (CPA).
Both re-appointments are for a further period of four years with effect from today, said a government statement.
It said: "President Tony Tan Keng Yam, in the exercise of powers vested in him by Article 37B(1)(b) of the Constitution of the Republic of Singapore and on the advice of Prime Minister, has re-appointed Mr J Y Pillay as a member of the Presidential Council of Advisers (CPA)."
Mr Pillay was also sworn-in and reappointed as the Person Exercising the Functions of the Office of the President for a further period of four years with immediate effect.
The appointment and swearing in ceremony, which was conducted in the Istana today, was witnessed by Prime Minister Lee Hsien Loong and members of the CPA.
Mr Pillay was first appointed to the CPA on January 2, 2001, and has served as Chairman of the CPA since September 2, 2005.
As Chairman of the CPA, Mr Pillay exercises the functions of the office of the President in the absence of the President. If he is unavailable, this duty then falls on the Speaker of Parliament.