O'Fallon Township High School District 203, Illinois
O'Fallon Township High School District 203 is a secondary (high school) district in St. Clair County, Illinois, for grades 9–12. About 44,393 people live in it (2020–2024 estimate). It covers 48.7 sq mi (126 km²) of land.
- Population, 2020–2024 estimate
- 44,393 ± 924
- Grades
- 9–12
- Type
- Secondary (high school) district
- County
- St. Clair County
- Land area
- 48.7 sq mi (126 km²)
- Median household income
- $104,651 ± $6,851
- Median home value
- $289,300 ± $10,725
- Water area
- 0.66 sq mi (1.7 km²)
- State
- Illinois
- Census code (GEOID)
- 1729790
- Coordinates (central point)
- 38.604605, -89.906392
These coordinates mark a central point for the district, not a school or an address. Population, income and home value: U.S. Census Bureau, American Community Survey 2020–2024 5-year estimates, ± margin at 90% confidence; checked on October 20, 2026.
Towns, townships and communities in O'Fallon Township High School District 203, largest first
- O'Fallon (city)32,262 people
- O'Fallon Township26,785 people
- Shiloh (village)14,572 people
A town, township, city or borough is listed when at least half its land is in the district; a community, when its central point is. Near a district line, an address can belong to the district next door.
Bordering secondary (high school) districts, nearest first
- Belleville Township High School District 2019.8 mi southwest
These share a boundary with O'Fallon Township High School District 203. Distances are straight lines between central points.
Before using this answer for enrollment
A district boundary doesn’t decide which school a student attends; the district’s attendance zones and rules do. Confirm the full address and grade with O'Fallon Township High School District 203 before you rely on it.
See its schools and enrollment on NCES ↗
Find the school district where you are now or find your town or township.