SourceMr Mandela led South Africa's transition from white-minority rule in the 1990s, after 27 years in prison for his political activities.
He had been receiving intensive medical care at home for a lung infection after spending three months in hospital.
Announcing the news on South African national TV, President Jacob Zuma said Mr Mandela was at peace.
"Our nation has lost its greatest son," Mr Zuma said.
With the death of a rather renowned world figure, what is your take on the man, his life, and his legacy?