The surname Fitzpatrick is the anglicised form of the Irish Mac Giolla Phádraig — meaning “son of the devotee of Patrick”. Fitzpatrick is unusual in having a ‘Fitz-‘ prefix despite being native Gaelic, not Norman.[1]
Quick Facts
| Irish form | Mac Giolla Phádraig |
| Modern Irish | Mac Giolla Phádraig |
| Meaning | Son of the devotee of patrick |
| Origin | Gaelic royal patronymic — Kings of Ossory |
| Historical regions | Kilkenny, Laois (Ossory) |
| Modern rank | Top 40 most common surnames in Ireland |
| Pronunciation | fits-PAT-rik (English) · MOK GIL-uh FAW-rig (Irish) |
Meaning & Etymology
Fitzpatrick is unusual in having a ‘Fitz-‘ prefix despite being native Gaelic, not Norman.[1]
The name is the anglicised form of Mac Giolla Phádraig, meaning ‘son of the servant (or devotee) of Patrick’ — referring to Saint Patrick.[2]
The family converted the Mac to Fitz in the 16th century under Tudor pressure to adopt more English-sounding names, despite being one of the oldest Gaelic royal dynasties.
The Mac Giolla Phádraig were kings of Ossory — a medieval Irish kingdom straddling modern Kilkenny and Laois.
Historical Fitzpatrick Septs
There is rarely a single family behind a major Irish surname. Edward MacLysaght — the gold-standard source for Irish surname history — identifies distinct historical septs that all anglicised to Fitzpatrick, often with no kinship to one another.[2]
The Kings of Ossory
The Mac Giolla Phádraig were the royal dynasty of Osraige — the kingdom of Ossory, which corresponded to modern County Kilkenny and parts of Laois. They ruled from at least the 5th century and maintained independence through both the Viking and Norman invasions. Their royal seat was at Cashel — not the Rock of Cashel, but a separate Cashel in Ossory.[1][2]
The Barons of Upper Ossory
Under Henry VIII, the family submitted to the Crown and received an English peerage — Baron of Upper Ossory — while being required to anglicise the Mac to Fitz. Despite this they remained Gaelic speakers and Catholic for generations.[1][2]
Famous Bearers
- John Fitzpatrick — 17th-century Irish commander in the Confederate Wars.
- Kathleen Fitzpatrick — Australian historian and writer; Irish-Australian descent.
- Benny Fitzpatrick — Scottish footballer of Irish descent.
- Sean Fitzpatrick — New Zealand rugby captain (All Blacks) of Irish descent.
Spelling Variants & Anglicisations
Over centuries of anglicisation, translation, and emigration, the Fitzpatrick name has taken many forms in English and Irish:
- Fitzpatrick · FitzPatrick · Fitz-Patrick
- Kilpatrick (Scottish cognate)
- Mac Giolla Phádraig (Irish)
- McGilpatrick (rare older anglicisation)
Where to Visit if Your Name is Fitzpatrick
If you carry the Fitzpatrick name and want to walk the ground your ancestors once held, here are the regions of Ireland that are your strongest historical anchors:
- County Kilkenny — the ancient kingdom of Ossory and the Mac Giolla Phádraig heartland. Visit Kilkenny Castle, Jerpoint Abbey, and the Dunmore Cave (where a Viking massacre of local Gaels — likely including Fitzpatricks — was recorded in 928 AD).
- County Laois — the northern half of historical Ossory. Visit the Rock of Dunamase, the ruined stronghold overlooking the Slieve Bloom Mountains.
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Subscribe Free →Sources
- Wikipedia: Wikipedia (en) — consolidated etymology and modern rank [link]
- Maclysaght: MacLysaght, Edward. Irish Families: Their Names, Arms and Origins. 1957, Hodges Figgis. The standard scholarly reference on the origin and distribution of Irish surnames.
All facts above are sourced from the named references listed above. Page last verified April 2026.