What did the 1926 census show about Ireland?

The 1926 census — the first conducted by the Irish Free State — recorded a population of 2.97 million across 26 counties. Around half the workforce was employed in agricultural occupations. The most agricultural counties (Leitrim 47%, Mayo 46%, Roscommon 46%) went on to experience the largest population declines over the following century. Galway had the highest Irish speaker rate at 54%, reflecting the living Gaeltacht communities of the time. Dublin contained more one-room dwellings than all other counties combined — a record of the tenement housing crisis of the early state.

Which county lost the most population since 1926?

Leitrim experienced the largest population decline of any Irish county between 1926 and 2022, losing approximately 59% of its population over the century. Mayo lost around 25% and Roscommon around 19%. These were also the most agricultural counties in 1926, with nearly half their workforce employed in farming. In contrast, Kildare — already lower in agricultural dependency in 1926 — grew by 77% over the same period, driven by Dublin commuter demand and economic development along the M7 corridor.

Which county had the most Irish speakers in 1926?

Galway had the highest proportion of Irish speakers in 1926 at 54%, reflecting the strong Gaeltacht communities of Connemara and South Galway. Mayo followed at 46%, Kerry at 38%, with Clare and Donegal both at 35%. The 1926 figure measures habitual and native speakers — the living Gaeltacht of the time. Dublin City recorded just 7.5%, despite being the capital of a state that had made Irish a constitutional language just four years earlier.

Where can I explore the 1926 census data on a map?

IrelandInsights maps four county-level metrics from the 1926 census — agriculture workforce percentage, Irish speaker percentage, population change from 1926 to 2022, and one-room dwelling rates. Each metric is displayed as a choropleth map across all 26 counties. Hovering any county shows both the 1926 figure and, where available, a 2022 comparison — all four historical metrics on a single interactive map.

Ireland · Historical Census · 1926

Ireland 1926 census — county data mapped

The 1926 census was the first conducted by the Irish Free State — a snapshot of a nation two years after civil war, five years after independence. IrelandInsights maps four 1926 county metrics — agriculture, Irish speakers, one-room dwellings, and population change — directly alongside Census 2022, county by county across all 26.

What the 1926 census shows

Population 1926

2.97M

First Free State census

Population 2022

5.15M

+73% over 96 years

Agricultural workforce 1926

51%

→ under 4% by 2022

Biggest decline

Leitrim −59%

Population change 1926–2022

The agricultural west — and why it emptied

The most agricultural counties in 1926 are the same counties that lost population over the following century. This is not coincidence — it is the defining demographic story of modern Ireland.

County	Agriculture % 1926	Population change 1926–2022
Leitrim	47%	−59%
Mayo	46%	−25%
Roscommon	46%	−19%
Cavan	45%	−1%
Donegal	42%	+9%
Kildare	27%	+77%
Dublin	1–7%	+65%

The pattern is consistent and stark: counties where nearly half the workforce farmed the land in 1926 went on to lose population at scale. Kildare and Dublin — already low in agricultural dependency — absorbed the population the west and midlands shed.

Explore agriculture % by county →

Irish speakers in 1926 — the historic Gaeltacht

The 1926 census recorded Irish speaker rates by county under the definition of habitual or native speakers — a strict measure reflecting the living Gaeltacht communities of the time. Galway had the highest rate at 54%, followed by Mayo (46%), Kerry (38%), Clare (35%) and Donegal (35%). Dublin City recorded just 7.5%.

Note: The 1926 Irish speaker figure reflects native and habitual speakers — a strict definition tied to Gaeltacht communities. The 2022 census measures the question differently. The two figures are not directly comparable. IrelandInsights maps the 1926 data as a record of where the language lived in the first decades of the state.

Map Irish speakers by county 1926 →

Population change 1926–2022 — winners and losers

Kildare grew by 77% from 1926 to 2022 — the fastest-growing county in Ireland over the full century. Meath grew 71%, Dublin 65%, Wicklow 63%. At the other end, Leitrim lost 59% of its 1926 population — the largest county-level decline in the state.

Fastest growth	Change 1926–2022	Biggest decline	Change 1926–2022
Kildare	+77%	Leitrim	−59%
Meath	+71%	Mayo	−25%
Dublin	+65%	Roscommon	−19%
Wicklow	+63%	Sligo	−2%

Map population change 1926–2022 →

Housing in 1926 — one-room dwellings

The 1926 census recorded one-room dwellings as a measure of acute housing poverty. Dublin contained 27,351 — more than every other county in Ireland combined. These were the city tenements that drove the social housing programme of the following decades. In rural counties, one-room dwellings reflected isolated cottages rather than urban overcrowding.

Map one-room dwellings 1926 →

Place of birth in 1926

96.5% of Ireland's 1926 population was born in Ireland. The largest foreign-born group was from Great Britain (49,354 people) — many of them likely returned emigrants or the children of the pre-independence emigration wave. A further 35,132 had been born in Northern Ireland, and 9,405 in the United States.

The 1926 census is the first full picture of an independent Ireland — a country in which agriculture, emigration, and the Gaeltacht were not historical footnotes but present realities.

Explore the 1926 map

IrelandInsights maps all four 1926 county-level metrics alongside Census 2022 data. Hover any county to see its 1926 figure alongside its 2022 comparison — agriculture, Irish speakers, population change, and housing on a single live map.

Agriculture 1926 Irish speakers 1926 Population change Housing 1926

Ireland population growth → · Rural Ireland today → · How Ireland changed →

Primary sources · CSO Census 1926 scanned original volumes:
Vol. 1 — Population · Vol. 2 — Occupations · Vol. 3 — Religion & Birthplaces · Vol. 8 — Irish Language · All 1926 volumes
National Archives — search household returns · CSO Then and Now 1926–2022 · CSO Census 2022