How Ireland changed — a century of census data

Two censuses, ninety-six years apart. In 1926 Ireland had a population of 2.97 million, half its workers farmed the land, and the west was still populated. By 2022 the population had grown to 5.15 million — but the growth bypassed the same counties that started with the least.

The map that moved

In 1926, Ireland's population was spread across the island with notable density in the west and midlands. By 2022, it had concentrated decisively in the east — Dublin, Kildare, Meath, Wicklow — and in the cities of Cork and Galway. The pattern visible in the data is not random: it follows economic opportunity, transport, and the long shadow of agricultural dependency.

The agricultural trap — why Connacht emptied

Nationally, agriculture accounted for 51% of the Irish workforce in 1926. By 2022 that figure had fallen to under 4% — the most dramatic structural transformation of any sector in the history of the state. But the national figure masks a county-level story that is even more stark.

In 1926, nearly half the workforce in counties like Leitrim, Mayo, Roscommon and Cavan was employed in agricultural occupations. These were subsistence farming communities, working poor land, with few alternative industries and ready emigration routes to Britain and America. The correlation between high agricultural dependency in 1926 and population loss by 2022 is one of the clearest patterns in the data.

Kildare, by contrast, had just 27% of its workforce in agriculture in 1926 — and grew by 77% over the century. Dublin, with 1–7% agricultural dependency depending on area, grew by 65%. The counties that had already diversified away from farming by 1926 were the counties that grew.

• Leitrim (47% ag → −59% pop): The starkest case. Poor land, no urban centre, no railway connectivity in key areas. Emigration was continuous from the Famine through to the 1980s and beyond.
• Mayo (46% ag → −25% pop): Lost 34,720 people from its 1926 base of 137,970. Castlebar and Westport grew while rural areas hollowed out.
• Roscommon (46% ag → −19% pop): Down 13,297 from its 1926 base. The only Connacht county with a railway lost it — compounding the isolation.
• Kildare (27% ag → +77% pop): The commuter belt effect. Naas, Maynooth, Celbridge, Newbridge — all grew as Dublin expanded outward along the M7 and rail corridors.
• Meath (35% ag → +71% pop): Navan, Ashbourne, Dunboyne — absorbed Dublin overspill. Agricultural land converted to housing at scale from the 1990s onward.

Dublin's hidden housing crisis — 1926

The 1926 census recorded 27,351 one-room dwellings in Dublin — more than every other county in Ireland combined. These were the tenements of the inner city: families of six or eight living in a single room in houses that had once been Georgian townhouses. The tuberculosis epidemic of the 1930s, the Iveagh Trust, the Corporation housing schemes of the 1940s and 50s — all of them are responses to what the 1926 census recorded.

The housing crisis of 2026 has different causes — shortage rather than overcrowding, the periphery rather than the centre. But the 1926 map of Dublin's one-room dwellings is a reminder that the city has faced acute housing stress before, and that it took a generation of public investment to resolve it.

The Gaeltacht in 1926

In 1926, Irish speaker rates were concentrated in the west — Galway (54%), Mayo (46%), Kerry (38%), Clare and Donegal (both 35%). These were living language communities, not heritage designations. The counties with the highest Irish speaker rates in 1926 were also among the most agricultural and the most affected by emigration over the following decades.

Dublin City recorded just 7.5% Irish speakers in 1926 — the capital of a state that had made Irish a constitutional language in 1922. The picture the census captures is of a language whose survival was rooted in the same rural communities that emigration was about to dismantle.

Religion in 1926

The 1926 census recorded Ireland as 92.6% Roman Catholic — but the Protestant geography was more varied than the national figure suggests. Wicklow had the highest Church of Ireland proportion at 5.8% (9,045 people), followed by Cavan (5%), Carlow (3.9%) and Donegal (3.9%). These patterns reflect plantation histories, the Pale, and the concentration of the Anglo-Irish landowning class in the eastern counties.

By 2022, the Church of Ireland nationally accounted for approximately 2.7% of the population — a decline that reflects both emigration of Protestant families and the broader shift in religious self-identification.

Who was living in Ireland 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, likely including returned emigrants and the families of those who had moved between the islands during the pre-independence period. A further 35,132 had been born in Northern Ireland, reflecting the newness of the border. 9,405 were born in the United States — a visible trace of the return flow from the emigrant communities of Boston, New York and Chicago.

1926 census overview →  ·  Population growth →  ·  Rural Ireland today →