Summary:
O Fallon Township HSD 203 has one listed school, serving grades 9–12: O Fallon High School, with 2,540 students. Its most important result is that in 2025–2026, proficiency was higher than the state’s in all nine reported subject-and-grade comparisons.
There is no meaningful top-to-bottom comparison among schools because O Fallon High is the only school listed; it is both the area’s highest- and lowest-scoring school by default. Its results stand out against the state instead: proficiency was about 7 to 15 percentage points higher across the nine measures, from grade 9 mathematics to grade 11 ELA. Across those comparisons, the school averaged 59% proficient versus 47% statewide, an advantage of about 12 percentage points. Graduation was also higher than the state rate, at 96% versus 90%.
Results show gains in some grades and declines in others, rather than improvement across the board. Grade 11 ACT proficiency rose in ELA, mathematics and science; grade 9 PreACT Secure results fell in ELA, from 75% to 70%, and science, from 61% to 56%, while mathematics increased from 48% to 49%. SchoolDigger ranks the school 101st of 620, in the 84th percentile, with four stars for 2025–2026; its rank was 91st of 697 in 2023–2024 and 101st of 698 in 2024–2025. Context measures include a student–teacher ratio of 16.3 and 28% free/reduced lunch eligible, both for 2024–2025. Chronic absenteeism was 22% in 2025–2026, slightly below the state’s 24%.
Thank you for your feedback!