Despite being a veritable icon of Ireland, St. Patrick — the Emerald Isle's patron saint — was not Irish. As he explained in his autobiography, "Confessio," raiders kidnapped him from his native Roman Britain when he was 16 and enslaved him as a sheep herder in Ireland for six years.
The autobiography provides details surrounding St. Patrick's family, birthplace and journey back to Ireland after escaping slavery. It began (translation via Christian Classics Ethereal Library):
The modern-day location of the "settlement of Bannavem Taburniae" has long been contested; experts have not reached any definitive conclusion, as of this writing. As explained in "Saint Patrick Retold" by Roy Flechner:
After six years as a slave in Ireland, he managed to flee back to his homeland and reunite with his family. In one of the most famous passages of "Confessio," he tells of a dream he had that inspired him to return to Ireland and become a missionary.
In sum, while it is uncertain which town in Roman Britain St. Patrick was born in, historians know from his autobiography, "Confessio," that he was not Irish, nor was he born in Ireland.