The President, Mrs McAleese, and the Taoiseach, Mr Ahern, led the congratulations to Cian O'Connor on his Olympic gold medal for showjumping.
Mrs McAleese paid tribute to O'Connor and the entire Irish equestrian team on "a superb performance" last night.
"Winning a gold medal for Ireland is a tremendous achievement and one we are all very proud of. We look forward to welcoming Cian and the team home along with all the Irish athletes who have given their very best for Ireland in Athens this year."
Mr Ahern, who watched the competition at home in Drumcondra, congratulated O'Connor.
"Cian showed enormous courage and determination with his performance in the final round tonight in Athens. Ireland has a proud history in showjumping events and this win is a victory which everyone in Ireland can be very proud of.
"I want to congratulate Cian and all the Irish showjumping team for their marvellous performances in what can only be one of the toughest show-jumping competitions witnessed." Mr Ahern paid tribute to the entire Irish Olympic team.
"All of Ireland should be proud of the performances put in after many years of hard work by all the athletes in the Irish team over the past two weeks."