President Michael D Higgins has led the tributes from Ireland.
In a statement, he said the South African would be remembered for all time as one of the greatest and most heroic leaders the world has ever known.
The Taoiseach Enda Kenny said a great light has been extinguished - and he said Mr Mandela's journey had transformed not just South Africa, but humanity itself.
Whilst the Tanaiste Eamon Gilmore said everyone felt part of his extended worldwide family, sharing in the sadness at his death and the celebration of his life.
