Mason, Illinois Demographics & Population 2026

A note before these figures: with a population of 467, Mason'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

Mason is a small community located in Illinois, within Effingham County. The total population is 467. It ranks as the 954th most populous out of 1,445 Census-designated places in Illinois.

Age Demographics

The median age in Mason is 29.8 years. This is 24% lower than the state median of 39.0 years. With 32.3% of the population under 18, Mason has a notably young demographic profile, suggesting a family-oriented community.

Economy, Income & Housing

The median household income in Mason is $65,455. This is 22% lower than the state median of $83,390. It is also 19% lower than the national median of $80,734. The poverty rate stands at 35.5%. This is 201% 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 7.7%. This is 32% higher than the state rate of 5.8%. The median home value is $82,900. Housing costs are 69% lower than the state median of $263,300. With a home-value-to-income ratio of just 1.3x, Mason is one of the most affordable housing markets in the area. 78.0% of occupied housing units are owner-occupied. This homeownership rate is 16% higher than the state average of 67.1%.

Race & Ethnicity

Mason has a predominantly White (non-Hispanic) population, comprising 94.7% of all residents. Hispanic or Latino residents account for 2.1%. The White (non-Hispanic) population is significantly higher than the state average (94.7% vs 58.1%). The Hispanic or Latino population (2.1%) is well below the state average of 18.8%. The Asian population (1.7%) is well below the state average of 5.9%.

Education

5.0% 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 87% 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 86.4%.

Data Sources & Methodology

All demographic data for Mason, 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.