Grand Detour, Illinois Demographics & Population 2026

A note before these figures: with a population of 297, Grand Detour's ACS estimates come from a small number of survey responses and carry wide margins of error. Individual percentages below — particularly rates that round to 0% or 100% — are approximations, not precise measurements. See data.census.gov for the published margins of error.

Population Overview

Grand Detour is a small community located in Illinois, within Ogle County. The total population is 297. It ranks as the 1083rd most populous out of 1,445 Census-designated places in Illinois.

Age Demographics

The median age in Grand Detour is 51.6 years. This is 32% higher than the state median of 39.0 years. Only 14.1% of residents are under 18, indicating fewer families with children.

Economy, Income & Housing

The median household income in Grand Detour is $76,406. This is 8% lower than the state median of $83,390. It is also 5% lower than the national median of $80,734. The poverty rate stands at 3.0%. This is 74% lower than the state poverty rate of 11.8%. This exceptionally low poverty rate indicates strong economic prosperity across the community. The unemployment rate is 18.9%. This is 223% higher than the state rate of 5.8%. The median home value is $191,700. Housing costs are 27% lower than the state median of $263,300. With a home-value-to-income ratio of just 2.5x, Grand Detour is one of the most affordable housing markets in the area. 90.5% of occupied housing units are owner-occupied. This homeownership rate is 35% higher than the state average of 67.1%.

Race & Ethnicity

The largest racial or ethnic group in Grand Detour is White (non-Hispanic), making up 65.7% of the population. Hispanic or Latino residents account for 34.3%. The Hispanic or Latino population is significantly higher than the state average (34.3% vs 18.8%).

Education

27.1% of residents aged 25 and older hold a bachelor's degree or higher. This is 28% lower than the state rate of 37.9%. Nationally, 35.7% of adults hold at least a bachelor's degree. The high school graduation rate (or equivalent) is 85.7%.

Data Sources & Methodology

All demographic data for Grand Detour, Illinois is sourced from the U.S. Census Bureau's American Community Survey (ACS) 2020–2024 5-Year Estimates. The ACS collects data from approximately 3.5 million households annually and pools five years of responses so that even small communities can be measured, though the margin of error widens as the population falls. Comparisons are made against Illinois state averages and national averages calculated from the same dataset. Rankings reflect the city's position among all 1,445 Census-designated places in Illinois. Read more about how these figures are produced on our methodology page, or visit data.census.gov for official data.