Onalaska, Wisconsin Population

Current Population

20,297

Estimated July 1, 2025

+1,439 residents(+7.6%)since 2020

Annual change+2.1%2024–2025

Latest Official Census

18,803

2020 Census

cityLa Crosse County

Population Over Time

Estimated population changed from 18,858 in 2020 to 20,297 in 2025.

Annual population estimates by year.
Year	Population	Change	% change
2020	18,858	—	—
2021	19,014	+156	+0.8%
2022	19,349	+335	+1.8%
2023	19,592	+243	+1.3%
2024	19,873	+281	+1.4%
2025	20,297	+424	+2.1%

2020 Census (official count): 18,803

Census History

Official Decennial Census counts. Each is an enumeration taken on April 1 of its census year, separate from the annual estimates above.

Official Decennial Census counts by census year.
Census	Population
2010 Census	17,736
2020 Census	18,803

Insights

Onalaska's population grew 6% from 2010 to 2020.
Source: U.S. Census Bureau — 2020 Census Redistricting Data (P.L. 94-171), table P1
How this was determined
Strongest eligible observation in category "change" (score 65.55, confidence 75); chosen from 1 eligible candidate(s).
Compared against: U.S. places
Confidence: 75/100
Onalaska is Wisconsin's 41st-largest incorporated place by population.
Source: U.S. Census Bureau — Subcounty Resident Population Estimates (SUB-EST2025), Vintage 2025
How this was determined
Strongest eligible observation in category "perspective" (score 65.25, confidence 85); chosen from 1 eligible candidate(s).
Compared against: incorporated places in Wisconsin
Confidence: 85/100

Sources & Methodology

The current population figure is an annual estimate from the U.S. Census Bureau's Population Estimates Program. The 2020 Census is shown separately as the official benchmark.

Current estimate — 20,297 · July 1, 2025

U.S. Census Bureau — Subcounty Resident Population Estimates (SUB-EST2025), Vintage 2025

Official Census — 18,803 · April 1, 2020

U.S. Census Bureau — 2020 Census Redistricting Data (P.L. 94-171), table P1

These figures can differ because the Census and annual population estimates are produced at different times using different methods. Both are shown so you can distinguish the most current estimate from the official Census benchmark.

How the change since 2020 is calculated

Both endpoints come from the same Census Bureau Population Estimates Program release, so the comparison is like for like: 18,858 on July 1, 2020 and 20,297 on July 1, 2025. The change is the later estimate minus the earlier one (+1,439), and the percentage is that change divided by the 2020 estimate (+7.6%). The Decennial Census count is never used as an endpoint here — it is an enumeration on a different reference date, produced by a different method, so subtracting one from the other would measure the difference between two methods as well as the change in population.