S. R. Nathan, 6th President of Singapore (b. 1924)
Sellapan Ramanathan ( ; 3 July 1924 – 22 August 2016), often known as S. R. Nathan, was a Singaporean politician who served as the sixth President of Singapore between 1999 and 2011.

Having been elected in uncontested elections in both 1999 and 2005 presidential election, Nathan is Singapore's longest-serving president.In 2009, Nathan surpassed Benjamin Sheares to become Singapore's longest-serving president. He was reportedly considering re-election, but announced on 2 July 2011 that he would not run for re-election.

Nathan suffered a stroke on 31 July 2016 and was taken to Singapore General Hospital's Intensive Care Unit. He died in hospital on 22 August, aged 92.