Ireland has a population of approximately 5.2 million people in 2025, making it the 121st most populous country in the world. That figure refers to the Republic of Ireland, which occupies about five-sixths of the island in the North Atlantic; the remaining territory, Northern Ireland, adds another 1.9 million and is part of the United Kingdom. The republic's population is now the largest it has been since the years immediately before the Great Famine of the 1840s.
How Ireland's Population Compares
With 5.2 million residents, Ireland is one of the smaller members of the European Union by headcount, sitting between Slovakia and Norway in size. Its population density is roughly 74 people per square kilometre, well below the EU average and a reflection of the country's many sparsely populated rural counties in the west and midlands. For comparison, neighbouring Great Britain houses more than 65 million people, while the wider island of Ireland holds around 7.1 million when Northern Ireland is included. Despite its modest size, Ireland punches far above its weight economically, hosting the European headquarters of many of the world's largest technology and pharmaceutical companies.
A Population Shaped by Famine and Emigration
Ireland's demographic story is among the most dramatic anywhere. In 1841 the island supported roughly 8.2 million people. The Great Famine of 1845 to 1852, caused by repeated failures of the potato crop, killed about a million through starvation and disease and drove more than a million more to emigrate, mostly to North America and Britain. Emigration then became a structural feature of Irish life for over a century, and the population of what is now the republic fell to a low point of around 2.8 million in the 1960s. Only in recent decades has sustained growth returned. Remarkably, it has taken roughly 180 years for the country to climb back toward its pre-Famine level.
Growth and Trends Today
Ireland is currently one of the fastest-growing nations in the European Union, expanding at around 1.1% per year. This growth is driven by three forces working together:
- Natural increase: Ireland's fertility rate of about 1.7 children per woman is above the EU average, so births still comfortably outnumber deaths.
- Returning emigrants: Many Irish citizens who left during economic downturns have come home as job prospects improved.
- Immigration: Strong demand for workers in technology, healthcare, and construction has attracted large numbers of newcomers from across Europe and beyond.
Projections suggest the population could approach 6 million by 2050. Ireland also has one of the youngest populations in Western Europe, with a median age of roughly 38 years, which helps sustain its growth and labour supply.
Where People Live: The Major Cities
Ireland's population is heavily concentrated on the eastern side of the island and in a handful of urban centres. Dublin, the capital, anchors a metropolitan area of about 1.4 million people, roughly a quarter of the entire country. It is the engine of Ireland's modern economy and home to the European bases of firms such as Google and Meta. Cork, the second city, has a metro population of around 210,000 and serves as a major southern port and pharmaceutical hub. Galway, with about 80,000 residents, is the cultural heart of the Atlantic west coast and a lively university town. Limerick and Waterford round out the larger cities. Outside these centres, much of the country remains rural, with small towns and villages dotting the landscape.
A Changing Society
For most of its history Ireland was one of Europe's most ethnically and religiously homogeneous countries, but the picture has shifted rapidly since the 1990s. Today around 12% of residents were born abroad, bringing new languages, cuisines, and communities to Irish towns and cities. Irish (Gaeilge) and English are both official languages; English dominates everyday life, though Irish is taught in schools and spoken daily in the Gaeltacht regions of the west. Religious identity has also transformed: while about 69% of the population still identifies as Roman Catholic, that share has fallen sharply from over 90% in the mid-twentieth century, and weekly attendance has declined even further. You can learn more in our ireland country guide.
Frequently Asked Questions
What is the population of Ireland in 2025?
The Republic of Ireland has roughly 5.2 million people in 2025. If Northern Ireland is included, the whole island holds about 7.1 million.
Why is Ireland's population still recovering from the Famine?
The island's population peaked at about 8.2 million in 1841 before the Great Famine and more than a century of heavy emigration cut it roughly in half. Sustained recovery only began in recent decades, so the republic has only just surpassed its early-1840s level.
What is the largest city in Ireland?
Dublin is by far the largest city, with a metropolitan area of about 1.4 million people, accounting for around a quarter of the country's total population.
How big is the global Irish diaspora?
Estimates of people worldwide who claim Irish ancestry range from 70 to 80 million, roughly 15 times the population living in Ireland today, a legacy of generations of emigration.