The surname Fitzpatrick is the translation of Mac Giolla Phádraig from the original Irish to English. It is the only surname with the Fitz prefix of Irish origin. All others are of Norman descent. Giolla Phádraig (the devoted of St. Patrick) was King of Ossory, a kingdom in Leinster in Ireland. According to Carrigan, this kingdom was founded by Aengus Osrith who flourished some time about the latter half of the second century of the Christian era. Giolla Phádraigs reign commenced some eight centuries later in 976 AD and he reigned until he was slain in 996 AD. His sons were styled Mac Giolla Phádraig (son of Giolla Phádraig). As part of the colonisation of Ireland by England, natural Irish names had to be restyled in the English format. Mac Giolla Phádraig was anglicised as Fitzpatrick.

By far the most important branch of the sept is the family whose Chief was known as Lord of Upper Ossory. At one time he was almost royal ruler over Laois and neighboring Kilkenny. Following the Anglo-Norman invasion in the late 12th century, their power was vastly diminished by the ascendancy of the Ormond Butlers and other English settlers. Although their patrimony was restricted to Upper Ossory, the Fitzpatricks were by no means dispossessed of all their property. They were one of the original great Irish families to submit to Henry VIII, and as a result, in 1541, Brian, the first to assume the surname Fitzpatrick in place of Mac Ǵolla Phádraig, was created Lord Baron of Upper Ossory. In the 17th century, the Fitzpatricks lost considerable territory through their staunch support of James II. Nevertheless, the head of the sept received a peerage in 1714. Records from 1878 show that no less than 22,000 acres of the finest land in Ossory was owned by the family.

The clan name is found throughout the world and several individuals and families have been prominent. Apart from the Lords and Earls of Upper Ossory, also prominent was Brian Fitzpatrick (1585-1652), Vicar Apostolic of Ossory, who was murdered by Cromwellian soldiers. He was instrumental in saving the "Book of the O'Byrne", which he had transcribed, from destruction. The family of Sir Percy Fitzpatrick made a major contribution to the political formation of South Africa. Major Thomas (Broken-Hand) Fitzpatrick, from Cavan, Indian Agent to the Sioux, Cheyenne and Arapaho tribes brought peace to the plains Indians of North America in 1851 at Fort Laramie. Patrick Fitzpatrick (1792-1865) was a trusted colleague of Daniel O'Connell. Fitzpatricks have also contributed, with significant influence and success, in high office in Ireland, England, Canada, India and the United States.

Modern variations of the name:
Fitzpatrick, Mac Giolla Phádraig, MacGilpatrick, Kilpatrick, MacKilpatrick, McIlpatrick, MacSéartha, Shera, Fitz, Fitch, Patrick, Parrican, Parogan, Patchy

Arms: Sable, a saltire argent, on a chief azure three fleur-de-lys or. Crest: A dragon reguardant vert surmounted of a lion guardant sable, dexter paw on the dragon's head. Mottos: Ceart Láidir Abú (Might is right). and Fortis sub forte fatiscet (The brave may yield to the brave).

The emblazon of Crest, Arms and Motto on this page was specially prepared and donated to the Fitzpatrick - Mac Giolla Phádraig - Clan Society by Eddie Geoghegan in 2000 AD to whom we extend our grateful thanks. The emblazon is a composite arrangement which uses a crest from one source, a chief and shield from a second source and a motto from a third source.