Population in Frankfort, IL

Population in Frankfort, IL was 21,365 in 2025, according to the U.S. Census Bureau. That is up 1% from 2024. That is the 113th highest of 225 cities in 2025.

2025, persons21,365
Change on 2024+1%
Series high21,3652025
Series low20,3142020

Population in Frankfort, IL, 2020 to 2025

20.3K20.5K20.8K21K21.3K21.5K2020202120222023202420252020: 20,314 persons2021: 20,523 persons2022: 20,706 persons2023: 20,981 persons2024: 21,158 persons2025: 21,365 persons
persons. Source: U.S. Census Bureau, Annual estimates of the resident population for incorporated places, 1 July (Population Estimates Program, subcounty totals). Retrieved 2026-10-12, published 2026-05-14.
All 6 values
Periodpersons
202521,365
202421,158
202320,981
202220,706
202120,523
202020,314

Compared with Illinois and United States

Place2025
Frankfort, IL21,365
Illinois12,719,141
United States341,784,857

Rankings

Definition

Resident population. Spain and the EU: 1 January, with Spanish figures from the official municipal register (Padrón). Norway: Statistics Norway, 1 January. United States: Census Bureau population estimates for 1 July. United Kingdom regions and local authorities: Office for National Statistics estimates for 30 June. Other countries and the World: World Bank mid-year estimates, which count all residents regardless of legal status or citizenship.

The World Bank series exists for every country, so use it (through compare) to rank countries on one basis.

How to cite

U.S. Census Bureau. Annual estimates of the resident population for incorporated places, 1 July (Population Estimates Program, subcounty totals). https://www2.census.gov/programs-surveys/popest/datasets/2020-2025/. Retrieved 2026-10-12.

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Questions

What is the population in Frankfort, IL?

Population in Frankfort, IL was 21,365 in 2025, according to the U.S. Census Bureau. That is up 1% from 2024. That is the 113th highest of 225 cities in 2025.

Where does this figure come from?

U.S. Census Bureau. Annual estimates of the resident population for incorporated places, 1 July (Population Estimates Program, subcounty totals). Retrieved by Invokely on 2026-10-12.

What was the highest population in Frankfort, IL?

21,365 in 2025, the highest value since 2020 in this series.

Population elsewhere in Illinois

All statistics for Frankfort, IL