Irish Population in Wisconsin by County : 2025 Ranking & Insights

According to U.S. Census estimates, the Irish population in Wisconsin totals 608,721. Every county in the state reports a non-zero population, with Dane County leading at 72,732, followed by Milwaukee County (70,488) and Waukesha County (50,332). This demographic analysis ranks all counties in Wisconsin 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 Wisconsin

View All
  • 1
    Dane County
    Irish population in Dane County is 72,732
    12.88% of Dane County population is Irish
  • 2
    Milwaukee County
    Irish population in Milwaukee County is 70,488
    7.60% of Milwaukee County population is Irish
  • 3
    Waukesha County
    Irish population in Waukesha County is 50,332
    12.30% of Waukesha County population is Irish
  • 4
    Brown County
    Irish population in Brown County is 25,565
    9.49% of Brown County population is Irish
  • 5
    Rock County
    Irish population in Rock County is 21,908
    13.36% of Rock County population is Irish

Overview of Irish population in Wisconsin

  • Population Count and Percentage: American Community Survey show Wisconsin contains 608,721 Irish residents (10.3% of 5.9 million total state population), positioning the state at the 60th percentile nationally among U.S. states for Irish population concentrations.
  • Comparison to State and National Averages: U.S. Census data records indicate Wisconsin's Irish population of 10.3% exceeds the national average of 9.4% by a factor of 1.1.
  • Share of Total National Population: Official American Community Survey document Wisconsin's 608,721 Irish residents constitute 2% 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 data show Wisconsin maintains 11.2 Irish Americans per square mile compared to the national average of 8.8, indicating higher demographic concentration relative to national averages.
  • Need additional overviews? Extended research data available for purchase and license. ➔

72 Counties in Wisconsin Ranked by Irish Population

View Methodology
American Community Survey data [1] show Irish populations across every county in Wisconsin, with demographic distributions ranging from the highest population in Dane 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 Wisconsin ranked by Irish population count
Rank by Irish Population
County
Irish Population
% of Total County Population
% of Total Wisconsin Irish Population
5 Year Rank Trend
1 Dane County 72,732 12.88% 11.95%
2 Milwaukee County 70,488 7.60% 11.58%
3 Waukesha County 50,332 12.30% 8.27%
4 Brown County 25,565 9.49% 4.20%
5 Rock County 21,908 13.36% 3.60%
6 Racine County 19,969 10.14% 3.28%
7 Outagamie County 18,674 9.75% 3.07%
8 18,128 10.76% 2.98%
9 16,918 9.87% 2.78%
10 16,541 13.75% 2.72%
11 14,836 10.80% 2.44%
12 14,463 13.72% 2.38%
13 11,227 8.13% 1.84%
14 10,969 10.32% 1.80%
15 10,696 11.28% 1.76%
16 10,596 10.18% 1.74%
17 10,393 11.25% 1.71%
18 9,834 8.35% 1.62%
19 9,551 11.12% 1.57%
20 8,788 9.89% 1.44%
21 8,483 12.90% 1.39%
22 7,631 9.38% 1.25%
23 7,295 10.37% 1.20%
24 7,008 9.47% 1.15%
25 6,834 11.72% 1.12%
26 6,745 10.13% 1.11%
27 6,515 12.61% 1.07%
28 5,958 14.07% 0.98%
29 4,879 12.84% 0.80%
30 4,718 10.22% 0.78%
31 4,705 9.10% 0.77%
32 4,688 10.61% 0.77%
33 4,577 10.10% 0.75%
34 4,428 9.47% 0.73%
35 4,391 8.34% 0.72%
36 4,388 9.68% 0.72%
37 4,266 11.52% 0.70%
38 3,868 9.84% 0.64%
39 3,768 15.81% 0.62%
40 3,208 10.59% 0.53%
41 3,093 11.59% 0.51%
42 3,087 9.99% 0.51%
43 2,917 6.96% 0.48%
44 2,589 10.46% 0.43%
45 2,581 6.31% 0.42%
46 2,534 12.11% 0.42%
47 2,460 10.51% 0.40%
48 2,439 15.18% 0.40%
49 2,414 14.38% 0.40%
50 2,371 8.35% 0.39%
51 2,350 13.64% 0.39%
52 2,219 6.39% 0.36%
53 2,137 6.94% 0.35%
54 2,088 9.96% 0.34%
55 1,954 12.44% 0.32%
56 1,889 9.86% 0.31%
57 1,852 11.06% 0.30%
58 1,706 10.40% 0.28%
59 1,699 8.72% 0.28%
60 1,694 9.29% 0.28%
61 1,528 9.52% 0.25%
62 1,431 8.55% 0.24%
63 1,313 6.37% 0.22%
64 1,276 6.39% 0.21%
65 1,240 8.81% 0.20%
66 1,233 8.72% 0.20%
67 1,039 7.79% 0.17%
68 903 9.75% 0.15%
69 583 9.46% 0.10%
70 561 7.61% 0.09%
71 521 11.28% 0.09%
72 59 1.39% 0.01%
Need the complete table? Full rankings and the underlying data sets for California and other locations are available for purchase or license.

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 Wisconsin 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 Wisconsin 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.