Marcy Tizzard is assistant to Senator John McGlory from Boston, Massachusetts. In an attempt to court the Irish-American vote in a tough reelection battle, the bumbling senator's chief of staff, Nick, sends Marcy to Ireland to find McGlory's relatives or ancestors.
Marcy arrives at the fictional village of Ballinagra as it is preparing for the annual matchmaking festival. She attracts the attention of two rival professional matchmakers, Dermot and Millie as well as roguish bartender Sean.
The locals tolerate her genealogical search while trying to match her with various bachelors. Sean tries to woo Marcy despite her resistance to his boorish manners. After they have begun their romance, they return home to Sean's house one afternoon to find his estranged wife waiting for them. Marcy leaves Sean, upset that he did not disclose his marriage to her.
McGlory and Nick arrive in Ballinagra, although Marcy's been unable to locate any McGlory relatives. McGlory discovers Sean's wife's maiden name is Kennedy and brings her back to Boston as his fiancée just in time for the election, and wins by a small margin. While at the victory party, McGlory's father reveals privately to Marcy that the family is Hungarian, not Irish. The family name had been changed at Ellis Island when they immigrated, but as they settled in Boston with its large Irish population, he never told his son their true lineage.
Sean follows Marcy to Boston, and they reconcile.