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Clonmacnoise, County Offaly
Photograph: Ingo Mehling · CC BY-SA 3.0 · Wikimedia Commons
Province of Leinster

County Offaly

Uíbh Fhailí

“eev AL-ee” · the people of Failghe, from Uí Failghe, the descendants of Failghe

Known as The Faithful County. From the county motto, Esto Fidelis, be faithful. Which is a neat answer to a county that spent three centuries called King's County after Philip II of Spain, Mary I's husband.

Did you know? From 1845 to 1917 the largest telescope on Earth was not in London or Paris but at Birr Castle — the 'Leviathan of Parsonstown', which first revealed the spiral structure of nebulae now known to be galaxies.
A fact like this for every county and every age →

Compare with another county → · Printable one-page summary →

Offaly by the numbers
Leinster province 83,150 people · 2022 census 2,001 km² · 18th of 32 by size County town Tullamore -24% in the Famine · 146,857 people in 1841, 112,000 in 1851 (approx.) 12 baronies · 1,159 townlands 1930s folklore · the Schools' Collection ↗ 24 surnames 3 towns on the site 586 daily Irish speakers Highest point Arderin, 527 m 7 senior All-Irelands 30 notable people born here UNESCO: Birr (tentative list) 1,196 historic buildings recorded Everything on the site about Offaly ↓
Carlow Cavan Cork Donegal Dublin Clare Galway Kerry Kildare Kilkenny Laois Leitrim Limerick Longford Louth Mayo Meath Monaghan Offaly Roscommon Sligo Tipperary Waterford Westmeath Wexford Wicklow Antrim Armagh Down Fermanagh Londonderry Tyrone

Open the atlas ↗

The history of Offaly

At Lough Boora bog, stone axes, arrowheads and blades show people camping here between about 6800 and 6000 BC. The Dowris Hoard, found in a bog near Birr, is the largest collection of Bronze Age objects ever found in Ireland, and after Christianity came, Clonmacnoise was built beside the Shannon.

In Gaelic Ireland the land was three kingdoms: Uí Failghe of the O'Conor Faly in the east, which gives the county its name; Firceall of the O'Molloys in the centre, part of Meath; and Éile of the O'Carrolls in the south, part of Munster. The Tudor plantation swept them away, and an act of 1556 created King's County, named after Philip, Mary I's husband. As with Laois, no law after independence ever formally changed the name, and land deeds still say King's County.

Drawn from the History section of the Wikipedia article on County Offaly ↗, rewritten here and adding nothing it does not say; licensed CC BY-SA 4.0. The chronology above is this site's own; where the two differ, the article is the one to check.

The land — from Wikipedia

Offaly is the 18th largest of Ireland's 32 counties by area and the 24th largest in terms of population. It is the fifth largest of Leinster's 12 counties by size and the tenth largest by population.

Read the full article ↗ · Text from Wikipedia, licensed CC BY-SA 4.0.

Clans & surnames of Offaly
Bannon Ó Banáin Gaelic septs (several) · “descendant of Banán, a diminutive of bán, ‘white’” Behan Ó Beacháin Gaelic sept · “descendant of Beachán — from beach, 'bee'” Bergin Ó hAimheirgin Gaelic sept · “descendant of Aimhirgin, 'wondrous birth'” Carroll Ó Cearbhaill Gaelic sept · “descendant of Cearbhall, 'fierce in battle'” Colgan Ó Colgáin Gaelic sept · “descendant of Colga — from colg, 'sword' or 'thorn'” Corbett Corbaid Norman & Gaelic · “'son of Corbet' — from French corbeau, a raven” Corcoran Ó Corcráin Gaelic sept · “descendant of Corcrán, 'purple-faced'” Coughlan Ó Cochláin / Mac Cochláin Gaelic sept · “descendant or son of Cochlán — from cochall, 'cloak' or 'hood'” Deegan Ó Duibhginn Gaelic septs (several) · “descendant of Dubhcheann, ‘black head’” Dempsey Ó Díomasaigh Gaelic sept · “descendant of Díomasach, 'the proud'” Dooley Ó Dubhlaoich Gaelic sept · “descendant of Dubhlaoch — dubh, 'dark', and laoch, 'warrior'” Egan Mac Aodhagáin Gaelic learned family · “son of little Aodh” Flanagan Ó Flannagáin Gaelic sept · “descendant of Flannagán, 'little red one'” Guilfoyle Mac Giolla Phóil Gaelic sept · “son of the servant of St Paul” Hennessy Ó hAonghusa Gaelic sept · “descendant of Aonghus” Killeen Ó Cillín Gaelic septs (several) · “descendant of Cillín, a pet form of Ceallach” Madden Ó Madáin Gaelic sept · “descendant of Madán (from madadh, 'hound')” Malone Ó Maoileoin Gaelic learned family · “descendant of Maoileoin, 'devotee of St John'” Minogue Ó Muineog Gaelic sept · “descendant of Muineog — a diminutive of manach, 'monk'” Molloy Ó Maolmhuaidh Gaelic sept · “descendant of Maolmhuadh, 'noble chief'” Mulhall Ó Maolchathail Gaelic sept · “descendant of Maolchathail, ‘servant of St Cathal’” O'Connor Ó Conchobhair Gaelic dynasty · “descendant of Conchobhar, 'lover of hounds'” Rigney Ó Raigne Gaelic sept · “a variant of Ó Raighne; Woulfe gives no meaning here” Shiel Ó Siadhail Gaelic sept · “descendant of Siadhal”

Tap a name for its full page — story, homeland map and neighbours. Or see all surnames from County Offaly, with the other counties each name is tied to.

Towns, saints and legends of Offaly

Towns. Tullamore Tulach Mhór (15,598, 2022), Edenderry Éadan Doire (7,888, 2022), Birr Biorra. What every town name means →

Saints. St Ciarán of Clonmacnoise (9 September).

Legends set here. Clonmacnoise — the ship in the air. On the atlas →

First names that belong here. Arlia, Ciarán, Flann, Calbhach.

Irish in Offaly today

At the 2022 census, 28,231 people in Offaly said they could speak Irish. 586 speak it every day outside school, and 1,536 weekly.

3 primary schools here teach entirely through Irish (2025/26, 281 pupils).

CSO, Census 2022, table SAP2022T3T2CTY. Every county compared →

The top of Offaly

Arderin (Ard Éireann), 527 metres, in the Slieve Bloom, on the county boundary and shared with a neighbouring county.

Rivers and loughs: River Shannon, River Boyne, River Brosna, Little Brosna River.

MountainViews, via Wikipedia. Every county's highest point → · Rivers and loughs →

Offaly in the All-Ireland

Hurling: 4 senior titles (1981, 1985, 1994, 1998); 3 finals lost.
Football: 3 senior titles (1971, 1972, 1982); 3 finals lost.

Every county's All-Ireland titles →

Born in Offaly

From Wikidata: people whose recorded birthplace is in the county, who have a Wikipedia article and are no longer living, with dates shown only where the article confirms them, ordered by how many languages Wikipedia covers them in. Traditional birthplaces of early saints are as Wikidata records them. Dates are left off where the sources disagree.

People in Offaly, census by census

Offaly had 146,857 people in 1841 and has 83,150 now (-43%). Its peak was 146,857 in 1841; its low point 51,308 in 1936, -65% of 1841. It has never regained the population it had before the Famine.

1821183118411851186118711881189119011911192619361946195119561961196619711979198119861991199620022006201120162022
131,088144,225146,857112,07690,04375,90072,85265,56360,18756,83252,59251,30853,68652,54451,97051,53351,71751,82957,34258,31259,83558,49459,11763,66370,86876,68777,96182,668

Census returns as tabulated in the county's Wikipedia article. All 32 counties, 1821 to today →

Hidden Offaly — the places the buses miss
  • Clonmacnoise
    The monastic city at the crossroads of Ireland, Shannon and Esker Riada, where kings were buried and Vikings, Irish and Normans all came to plunder.
  • Birr Castle Leviathan
    The largest telescope on Earth from 1845 to 1917 — a 72-inch mirror in a midland demesne, through which the spiral shape of galaxies was first seen.
On the ground in Offaly

Every pin is placed by its documented coordinates. All the monuments of Ireland →

Everything on the site about County Offaly

The county

History

Monuments and heritage

Coast and country

People and culture

Quick answers
What is the Irish name for County Offaly?

Uíbh Fhailí. Offaly is one of the 12 counties of Leinster (Cúige Laighean).

Who ruled County Offaly in the Middle Ages?

Around 1014 it was held by Mide (Kingdom of Meath); by 1450, O'More & O'Connor Faly. The full era-by-era chronology is on this page.

What surnames come from County Offaly?

Names historically associated with Offaly include Bannon, Behan, Bergin, Carroll, Colgan, Corbett, Corcoran, Coughlan, among others.

What does Uíbh Fhailí mean?

Uíbh Fhailí, said “eev AL-ee”, means the people of Failghe — from Uí Failghe, the descendants of Failghe. From the Gaelic kingdom of Uí Failghe, which lasted until 1550. Called King's County under English administration until 1922.

What is the population of County Offaly?

83,150 at the 2022 census, against 146,857 in 1841, before the Famine.

What is the county town of Offaly?

Tullamore. County Offaly covers about 2,001 km², which makes it the 18th largest of the 32 counties.

Who are famous people from County Offaly?

Among the best-known people born in Offaly are George Johnstone Stoney, George Brent, Mary Ward, John Joly, Lawrence Parsons, 4th Earl of Rosse, Robert Kennedy. The full list, with their birthplaces, is on this page.

What did the Famine do to County Offaly?

The census counted 146,857 people in Offaly in 1841 and 112,000 in 1851 (the 1851 figure is approximate): a change of -24% in ten years, through death and emigration.

Sources for this page

A clean copy for school projects or the family file; collapsed sections print in full.

The chronology of who held the county is this site's own reading of the standard histories onto today's county borders, and says so where the fit is rough. Quoted passages are marked and licensed. Spotted an error? Say so — corrections are credited.

Trace your ancestors in Offaly

Free, from the holding institutions. How to begin: the six-step guide → · Spotted an error on this page? Suggest a correction.