📊 What this ranking measures
Rankings are based on academic achievement — the share of students scoring proficient or above on state reading and math assessments (IAR 2023–24), ranked against other districts in the same state — not on spending, district size, or staffing. See full methodology →
All 27 Rated Districts in St. Clair County, IL
Sorted by rating, then state percentile
Best School Districts in St. Clair County, Illinois (2026)
This page lists the 27 public school districts headquartered in St. Clair County, Illinois that have a SchoolDistrictFinder rating, scored using IAR 2023–24 state assessment data. The county rank is simply their order here; the state percentile compares each district with every rated district in Illinois, which is how the 1–10 rating is set. Ratings are not comparable with districts in other states.
Districts are placed in the county of their NCES directory listing. A district's boundaries can cross county lines, and a home in St. Clair County may be served by a district headquartered next door — search your address or zip code to confirm.
Frequently Asked Questions
What is the best-rated school district in St. Clair County, Illinois? ▼
Among the 27 rated districts in St. Clair County, Illinois, the highest-rated is O'Fallon Township High School District 203 (O Fallon), rated 10/10 (Excellent) and in the 94th percentile of Illinois districts on IAR 2023–24 reading and math proficiency.
How are these rankings calculated? ▼
Each district's rating comes from the share of its students scoring proficient or above on state reading and math assessments (IAR 2023–24), percentile-ranked against all rated districts in Illinois and converted to a 1–10 scale. Full methodology here.