Since 1922, Leinster House in Dublin has served as the parliament building of the Republic of Ireland, before which it functioned as the headquarters of the Royal Dublin Society. Leinster House is responsible for politics, elections, passing laws and decision making.

The centre piece of Leinster House was originally the ducal palace of the Dukes of Leinster, first built in 1745–48 by the Earl of Kildare. In the history of aristocratic residences in Dublin, no other mansion matched Kildare House for its sheer size or status. When the Earl was made the first Duke of Leinster in 1766, the family's Dublin residence was renamed Leinster House. Its first and second floors were used as the floor model for the White House by Irish architect James Hoban, while the house itself was used as a model for the original stone cut White House exterior. Many additions have been made over the years.