Irish Population in Maryland by County : 2025 Ranking & Insights

According to U.S. Census estimates, the Irish population in Maryland stands at 574,470. Every county reports a non-zero population, with Montgomery County leading at 79,720, followed by Anne Arundel County (76,724) and Harford County (38,193). The combined total across counties is slightly lower than the statewide figure - a gap that may reflect rounding, data lag, or unassigned residents in certain census tracts. This analysis ranks all counties in Maryland by their Irish population, offering a localized perspective on how the community is distributed across the state.

Top 5 counties with the largest Irish population in Maryland

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  • 1
    Montgomery County
    Irish population in Montgomery County is 79,720
    7.54% of Montgomery County population is Irish
  • 2
    Anne Arundel County
    Irish population in Anne Arundel County is 76,724
    12.98% of Anne Arundel County population is Irish
  • 3
    Harford County
    Irish population in Harford County is 38,193
    14.55% of Harford County population is Irish
  • 4
    Frederick County
    Irish population in Frederick County is 37,597
    13.41% of Frederick County population is Irish
  • 5
    Baltimore city
    Irish population in Baltimore city is 32,696
    5.66% of Baltimore city population is Irish

Overview of Irish population in Maryland

  • Population Count and Percentage: American Community Survey documents Maryland with 574,470 Irish residents (9.3% of 6.2 million total state population), ranking the state at the 58th percentile nationally among U.S. jurisdictions for Irish demographic representation.
  • Comparison to State and National Averages: U.S. Census data documents Maryland's Irish population of 9.3% corresponding to the national average, placing the state as demographically representative of typical U.S. distribution patterns.
  • Share of Total National Population: Official American Community Survey document Maryland's 574,470 Irish residents constitute 1.8% of the nation's total Irish population of 31.2 million, providing the state with a measurable but modest share of the national demographic community.
  • Population Density per Square Mile: U.S. Census Bureau's American Community Survey document Maryland with 59.2 Irish Americans per square mile, more than six times the national average density of 8.8 per square mile, placing the state among jurisdictions with significantly elevated demographic concentrations nationally.
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22 Counties in Maryland Ranked by Irish Population

View Methodology
American Community Survey data [1] show Irish populations across every county in Maryland, with demographic distributions ranging from the highest population in Montgomery 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 Maryland ranked by Irish population count
Rank by Irish Population
County
Irish Population
% of Total County Population
% of Total Maryland Irish Population
5 Year Rank Trend
1 Montgomery County 79,720 7.54% 13.88%
2 Anne Arundel County 76,724 12.98% 13.36%
3 Harford County 38,193 14.55% 6.65%
4 Frederick County 37,597 13.41% 6.54%
5 Baltimore city 32,696 5.66% 5.69%
6 Carroll County 30,323 17.40% 5.28%
7 Prince Georges County 23,763 2.49% 4.14%
8 17,272 16.55% 3.01%
9 16,887 10.89% 2.94%
10 14,795 12.94% 2.58%
11 13,696 14.60% 2.38%
12 11,951 11.48% 2.08%
13 11,311 6.70% 1.97%
14 8,188 12.08% 1.43%
15 7,798 15.30% 1.36%
16 7,602 14.27% 1.32%
17 5,986 15.88% 1.04%
18 3,970 13.83% 0.69%
19 3,570 10.69% 0.62%
20 3,228 9.90% 0.56%
21 2,852 14.80% 0.50%
22 1,247 5.05% 0.22%
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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 Maryland 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 Maryland 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.