President Tony Tan Keng Yam and Prime Minister Lee Hsien Loong sent condolence messages following Nelson Mandela's death to South African President Jacob Zuma on Friday, while Foreign Minister K. Shanmugam sent a message to his counterpart, International Relations and Cooperation minister Maite Nkoana-Mashabane.
Mr Mandela was an eminent statesman whose unconditional sacrifices for his beloved country were second to none, Dr Tan wrote in a letter addressed to South African president Jacob Zuma.
"Your country has lost a true freedom fighter whose moral strength, loyalty and dedication transformed his beloved country into a harmonious and multi-racial nation that is today an example to nations around the world," he added.
Dr Tan recalled how he had the honour of introducing Mr Mandela at the 1997 Singapore Lecture, when the South African gave a speech during a state visit to Singapore.
"History will remember Mr Nelson Mandela as a great man and hero," he added.
Mr Lee, meanwhile, called the former South African president's death a "great loss to South Africa and mankind".
In a letter also addressed to Mr Zuma, Mr Lee said Mr Mandela had united a "deeply divided country after many years of apartheid".
"His humanity, courage and lifelong fight for freedom and equality inspired millions around the world.
"Singapore stands with South Africa in mourning Mr Mandela's passing. Our thoughts are with Mr Mandela's family and the people of South Africa during this period."
Mr Shanmugam, in a letter to Ms Nkoana-Mashabane, said Mr Mandela's "courage, determination and dedication are a legacy that will continue to inspire those of the present generation, and many more to come".