The President Mary McAleese and the Taoiseach Mr Ahern have both conveyed Ireland's good wishes to Cardinal Ratzinger on his election as Pope.
"You embody their hopes for greater unity among peoples and a more just and caring human family.
"Your guidance and leadership amid the complexities of modern life will be crucial. May your acceptance of this tremendous burden of service bear fruit in our world," she concluded.
The Taoiseach, Mr Ahern has also welcomed the appointment of Cardinal Razinger as pope.
In his message Mr Ahern said the scenes of "rejoicing and excitement" witnessed in St Peter's this evening expressed the goodwill "which people around the world, of all religions and none, will feel towards the new Pope."
Mr Ahern said the "awesome responsibility" that came with the papacy had "if anything, been increased" by the impact made by Pope Benedict's predecessor, the late Pope John Paul II.
"The worldwide impact of that pontificate, and the outpouring of sorrow at his death, represents a resource and a source of encouragement for the new Pope.
"It demonstrates that the world is waiting to hear his voice and receive his blessing," Mr Ahern continued.
Mr Ahern described Pope Benedict XVI as a man of "profound learning" and said he knew only too well the pressures which were awaiting him in the office of Pope. "He has chosen a name which associates him with the great mission of peace of the occupants of the See of Peter.
"All Irish men and women, whatever their tradition, will wish him well. He will have the prayers and good wishes of the Christian people of Ireland, especially, of course, of the Roman Catholic community, here as around the world," Mr Ahern's statement concluded.