Ireland 1926 census — county data mapped
The 1926 census was the first the Irish Free State ran — 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 — alongside Census 2022, across all 26 counties.
What the 1926 census shows
The agricultural west — and why it emptied
4 of the 5 most agricultural counties in 1926 — Leitrim, Roscommon, Mayo and Cavan — lost population over the next century. This is not coincidence. It is the defining demographic story of modern Ireland.
| County | Agriculture % 1926 | Population change 1926–2022 |
|---|---|---|
| Leitrim | 47% | −37% |
| Roscommon | 46% | −16% |
| Mayo | 46% | −20% |
| Cavan | 45% | −1% |
| Galway | 44% | +64% |
| Kildare | 27% | +327% |
| Dublin | 3% | +188% |
The pattern is clear: Leitrim, Roscommon, Mayo and Cavan each lost population between 1% and 37% of their 1926 level. Kildare and Dublin were already low in agricultural dependency (27% and 3% respectively) and grew by 327% and 188%. They absorbed the people the west and midlands shed.
Irish speakers in 1926 — the historic Gaeltacht
The 1926 census recorded the share of each county's population that spoke Irish. Galway had the highest rate at 47.4%, followed by Mayo (36.8%), Donegal (34.4%), Kerry (33.0%) and Clare (30.3%). Dublin recorded 7.8%.
Population change 1926–2022 — winners and losers
Kildare grew by 327% between 1926 and 2022 — the fastest of any county over the full century. Meath grew 251%, Dublin 188%, Wicklow 171%. At the other end, Leitrim lost 37% of its 1926 population — the largest county-level decline in the state.
| Fastest growth | Change 1926–2022 | Biggest decline | Change 1926–2022 |
|---|---|---|---|
| Kildare | +327% | Leitrim | −37% |
| Meath | +251% | Mayo | −20% |
| Dublin | +188% | Roscommon | −16% |
| Wicklow | +171% | Sligo | −2% |
Housing in 1926 — one-room dwellings
The 1926 census counted one-room dwellings as a sign of acute housing poverty. In Dublin, one-room dwellings accounted for 26.1% of permanent private households, against 7.5% nationally — the highest rate of any county. These were the city tenements that drove the social housing programme of the following decades. In rural counties, one-room dwellings meant isolated cottages rather than urban overcrowding.
Map one-room dwellings 1926 →Place of birth in 1926
96.6% of Ireland's 1926 population was born in Ireland. The largest foreign-born group came from Great Britain (49,354 people) — many likely returned emigrants or children of the pre-independence emigration wave. A further 35,132 were born in Northern Ireland, and 9,405 in the United States.
Explore the 1926 map
IrelandInsights maps all four 1926 county metrics alongside Census 2022 data. Hover any county to see its 1926 figure and its 2022 comparison — agriculture, Irish speakers, population change, and housing on a single live map.
All 26 counties — 1926 vs 2022 → · How Ireland changed → · Irish language 1926 →
Population growth 2016–2022 → · Rural Ireland today →
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