Oak Grove, Illinois Demographics & Population 2026

A note before these figures: with a population of 277, Oak Grove'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

Oak Grove is a small community located in Illinois, within Rock Island County. The total population is 277. It ranks as the 1107th most populous out of 1,445 Census-designated places in Illinois.

Age Demographics

The median age in Oak Grove is 58.8 years. This is 51% higher than the state median of 39.0 years. Only 9.4% of residents are under 18, indicating fewer families with children. 15.5% of residents are 75 or older, suggesting a significant retirement-age population with implications for healthcare services and senior housing.

Economy, Income & Housing

The median household income in Oak Grove is $40,972. This is 51% lower than the state median of $83,390. It is also 49% lower than the national median of $80,734. The poverty rate stands at 26.0%. This is 120% higher than the state poverty rate of 11.8%. With more than one in five residents living below the poverty line, economic hardship is a significant challenge for the community. The unemployment rate is 10.8%. This is 84% higher than the state rate of 5.8%. The median home value is $14,200. Housing costs are 95% lower than the state median of $263,300. With a home-value-to-income ratio of just 0.3x, Oak Grove is one of the most affordable housing markets in the area. 88.4% of occupied housing units are owner-occupied. This homeownership rate is 32% higher than the state average of 67.1%.

Race & Ethnicity

Oak Grove has a predominantly White (non-Hispanic) population, comprising 92.8% of all residents. Hispanic or Latino residents account for 2.5%. The White (non-Hispanic) population is significantly higher than the state average (92.8% vs 58.1%). The Hispanic or Latino population (2.5%) is well below the state average of 18.8%. The Asian population (1.8%) is well below the state average of 5.9%.

Education

3.1% of residents aged 25 and older hold a bachelor's degree or higher. This is among the lowest rates in the state, which may correlate with employment and income patterns. This is 92% 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 87.1%.

Data Sources & Methodology

All demographic data for Oak Grove, 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.