Seneca, Oregon Demographics & Population 2026

A note before these figures: with a population of 109, Seneca'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

Seneca is a small community located in Oregon, within Grant County. The total population is 109. It ranks as the 394th most populous out of 420 Census-designated places in Oregon.

Age Demographics

The median age in Seneca is 67.8 years. This is 68% higher than the state median of 40.4 years. Only 9.2% of residents are under 18, indicating fewer families with children. 17.4% 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 Seneca is $39,821. This is 52% lower than the state median of $83,011. It is also 51% lower than the national median of $80,734. The poverty rate stands at 22.0%. This is 84% higher than the state poverty rate of 11.9%. With more than one in five residents living below the poverty line, economic hardship is a significant challenge for the community. The survey records no unemployed residents in Seneca, which reflects the size of the sample rather than a labor market without joblessness. The median home value is $156,300. Housing costs are 67% lower than the state median of $477,600. The home-value-to-income ratio is 3.9x. 85.9% of occupied housing units are owner-occupied. This homeownership rate is 36% higher than the state average of 63.3%.

Race & Ethnicity

The largest racial or ethnic group in Seneca is White (non-Hispanic), making up 64.2% of the population. Hispanic or Latino residents account for 9.2%.

Education

19.2% of residents aged 25 and older hold a bachelor's degree or higher. This is 48% lower than the state rate of 36.8%. Nationally, 35.7% of adults hold at least a bachelor's degree. The high school graduation rate (or equivalent) is 73.7%.

Data Sources & Methodology

All demographic data for Seneca, Oregon 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 Oregon state averages and national averages calculated from the same dataset. Rankings reflect the city's position among all 420 Census-designated places in Oregon. Read more about how these figures are produced on our methodology page, or visit data.census.gov for official data.