Crowds welcome Obamas to Moneygall
23 May 2011 Last updated at 18:02 BST
Crowds lined the streets in Moneygall, which normally only has 300 residents, to welcome Mr Obama to the village that was home to his great-great-great grandfather, a shoemaker.
Locals greeted Mr Obama and First Lady Michelle Obama with cries of "Welcome home!" as they entered the village.
Mr Obama is visiting the Republic of Ireland at the start of a week-long tour of Europe.
Annita McVeigh reports.