Demographics & People — Seneca, Kansas
Population Overview
| Population (Census) | 2,139 |
| Estimated 2026 | ~2,000 |
| Median Age | 51.8 |
| Total Households | 889 |
| Family Households | 562 |
| Average Household Size | 2.24 |
| Diversity Index | 0.0873 (relatively homogeneous) |
Race & Ethnicity
| White | 2,090 |
| Black or African American | 3 |
| Asian | 0 |
| Hispanic or Latino | 97 |
Heritage & Ancestry
| Group | Count |
| German | 1,139 |
| Unclassified or not reported | 445 |
| American | 155 |
| English | 142 |
| Irish | 107 |
| Hispanic: Hispanic or Latino | 102 |
| Other groups | 94 |
| Hispanic: Mexican | 85 |
| Scottish | 44 |
| Czech | 37 |
Language
| English Only | 1,990 |
| Spanish | 45 |
| Population 5+ | 2,050 |
Veterans
| Veterans | 111 |
| Population 18+ | 1,584 |
Source: Census ACS 5-Year 2023; Census ACS 5-Year 2023, Table B01003; Census ACS 5-Year 2023, B19013. Data for Seneca, Kansas.