Sellapan Ramanathan, (born Cellappaṉ Rāmanātaṉ, 3 July 1924) is a
Singaporean politician who was the sixth
President of the Republic of Singapore. Usually referred to as
S. R. Nathan, he was first sworn in on 1 September 1999. In 1999 and 2005, he was elected President in
uncontested elections. In 2009, he surpassed
Benjamin Sheares to become Singapore's longest-serving President. His 12-year term ended on 31 August 2011. Since then, he has been the nation's only living former President.