How many people live in ?

Updated Apr. 6, 2026Refreshed annually
In 2024, there were about 54,700 people living in Whiteside County, IL. That makes Whiteside County the 24th-most populous county in Illinois. It is home to 0.43% of people living in the state.

54.7K

population of Whiteside County, IL (2024)

0.43%

County share of the Illinois population (2024)

About 54,700 people lived in Whiteside County, IL in 2024.

Population estimates, 2000–2024

What are Whiteside County, IL’s age demographics?

About 12,400 Whiteside County residents are aged 65 and older in 2024. That represents 22.7% of its population. For comparison, the age group represents 17.9% of Illinois' population and 18% in the US overall.
Another 11,900 Whiteside County residents, or 21.9% of the population, were children under 18. For comparison, the age group represents 21.2% of Illinois’s population and 21.6% in the US overall.


A higher share of Whiteside County, IL's population is aged 65 or older than the US as a whole.

Population estimates by age group, (2024)

What are Whiteside County, IL’s racial and ethnic demographics?

Non-Hispanic white residents make up 82% of the Whiteside County, IL population, higher than the national share of 57.5%.
In contrast, Whiteside County’s non-Hispanic Black or African American population accounts for 1.7%, below the 12.6% nationwide, and the Hispanic population makes up 13.9% of the county, compared with 20% nationally.
Racial and ethnic make up differ based on location. These figures reflect how people identified their race alone (not in combination with other races), and separate out Hispanic or Latino ethnicity, following Census reporting standards.

Whiteside County, IL has a higher share of a non-Hispanic white population than Illinois as a whole.

Population estimates by race and ethnicity, (2024)

The largest city or town in Whiteside County, IL is Sterling with about 14,500 residents in 2024.

Cities and towns in Whiteside County, IL ranked by population

Population (2024), includes only portions within county

Cities and towns in Whiteside County, IL ranked by population
City or townPopulation
1.

Sterling (pt.)

14,535
2.

Rock Falls (pt.)

8,614
3.

Morrison (pt.)

3,923
4.

Fulton (pt.)

3,581
5.

Prophetstown 

1,906
6.

Erie 

1,491
7.

Jordan 

841
8.

Albany (pt.)

832
9.

Tampico 

675
10.

Fenton 

558

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Methodology

USAFacts standardizes data, in areas such as time and demographics, to make it easier to understand and compare.

The analysis was generated with the help of AI and reviewed by USAFacts for accuracy.

Page sources

USAFacts endeavors to share the most up-to-date information available. We sourced the data on this page directly from government agencies; however, the intervals at which agencies publish updated data vary.