Irish Population in New Hampshire by County : 2025 Ranking & Insights

According to U.S. Census estimates, the Irish population in New Hampshire totals 282,555. Every county in the state reports a non-zero population, with Hillsborough County leading at 87,359, followed by Rockingham County (76,739) and Merrimack County (30,033). This demographic analysis ranks all counties in New Hampshire by their Irish population, offering insights into regional distribution patterns and highlighting county-level concentrations across the state.

Top 5 counties with the largest Irish population in New Hampshire

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  • 1
    Hillsborough County
    Irish population in Hillsborough County is 87,359
    20.57% of Hillsborough County population is Irish
  • 2
    Rockingham County
    Irish population in Rockingham County is 76,739
    24.20% of Rockingham County population is Irish
  • 3
    Merrimack County
    Irish population in Merrimack County is 30,033
    19.37% of Merrimack County population is Irish
  • 4
    Strafford County
    Irish population in Strafford County is 28,606
    21.71% of Strafford County population is Irish
  • 5
    Grafton County
    Irish population in Grafton County is 14,613
    15.93% of Grafton County population is Irish

Overview of Irish population in New Hampshire

  • Population Count and Percentage: American Community Survey show New Hampshire contains 282,555 Irish residents (20.4% of 1.4 million total state population), positioning the state at the 37th percentile nationally among U.S. states for Irish population concentrations.
  • Comparison to State and National Averages: U.S. Census data records indicate New Hampshire's Irish population of 20.4% exceeds the national average of 9.4% by a factor of 2.2.
  • Share of Total National Population: Official American Community Survey data indicates New Hampshire contains 282,555 Irish residents, representing less than 1% of the nation's total Irish population of 31.2 million, constituting a minimal fraction of the national demographic community relative to the state's overall population size.
  • Population Density per Square Mile: U.S. Census Bureau's American Community Survey data indicates New Hampshire's density of 31.6 Irish Americans per square mile exceeds the national average of 8.8 per square mile by three and a half times, establishing the state as a significant concentration center for Irish demographic communities.
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10 Counties in New Hampshire Ranked by Irish Population

View Methodology
American Community Survey data [1] show Irish populations across every county in New Hampshire, with demographic distributions ranging from the highest population in Hillsborough County to the lowest in $rank_n_geo_name. The table below provides broader statistics, including total population figures, density measures, and demographic distributions based on current ACS data for all counties included in this analysis*.
counties in New Hampshire ranked by Irish population count
Rank by Irish Population
County
Irish Population
% of Total County Population
% of Total New Hampshire Irish Population
5 Year Rank Trend
1 Hillsborough County 87,359 20.57% 30.92%
2 Rockingham County 76,739 24.20% 27.16%
3 Merrimack County 30,033 19.37% 10.63%
4 Strafford County 28,606 21.71% 10.12%
5 Grafton County 14,613 15.93% 5.17%
6 Belknap County 13,389 20.82% 4.74%
7 Carroll County 11,189 21.83% 3.96%
8 11,060 14.37% 3.91%
9 4,985 11.45% 1.76%
10 4,582 14.60% 1.62%
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Methodology

This ranking list is based on data from the American Community Survey (ACS) 5-Year Estimates, conducted by the U.S. Census Bureau. The ACS is one of the most reliable sources for understanding population trends across different locations, and it provides estimates for various racial and ethnic groups at city, county, state and all geography levels down to the Census block group.
This list ranks county in New Hampshire by their Irish population, using the most recent ACS data available.

How the Census defines Irish population

The U.S. Census Bureau allows people to self-identify their ancestry, meaning individuals can write upto ancestries when responding to the survey. In this ranking, we include everyone who identifies as having Irish ancestry, whether alone or in combination with another ancestry.
Here are a few important things to know about how ancestry is reported:
  • Some people identify as Irish alone, while others identify as Irish along with another race (such as Irish and German).
  • We’ve used the “Irish alone or in any combination” category unless noted otherwise, which gives a broader picture of the Irish population in each area.

How We Ranked the Data

This ranking is based on the total number of people who identified as Irish alone or in combination in county. To provide additional context, we’ve also included two key percentages:
  1. % of Total County Population – This shows what percentage of the total state population identifies as Irish .
  2. % of Total New Hampshire Irish Population – This tells us how much of the entire U.S. Irish population lives in that state.
To keep things simple, all population numbers have been rounded to the nearest whole number, and percentages are rounded to one decimal place. Because of rounding, some percentages may not add up to exactly 100%.

Things to Keep in Mind

Like all survey-based data, ACS estimates come with some limitations. Here are a few things to be aware of:
  • In places with very small Irish populations, the numbers may not be reported at all due to privacy protections or sampling variability in the survey.
  • Since the ACS is based on a sample, the numbers are estimates, not exact counts. That means they may slightly differ from other sources like the decennial U.S. Census.
  • County that don’t have any reported Irish population are not included in the ranking but are listed separately below for reference.
This ranking is meant to provide a clear, data-driven look at where Irish populations are most concentrated while keeping the numbers easy to understand.

Sources

  1. 2019-2023 5-Year Estimates.
  2. 2023.