Best Public Schools in Lemont, IL

Lemont, Illinois, has five schools—three elementary schools, one middle school and one high school—serving students from elementary through high school; all five have chronic absenteeism below the state rate. The clearest academic finding is that Old Quarry Middle School stands out in IAR English language arts, while all three schools with reported overall IAR results are above the state in both ELA and math.

Old Quarry has the highest reported IAR ELA result at 87%, compared with 68% at River Valley School and 67% at Central School; its lead over the next school is 19 points. In math, River Valley is narrowly highest at 70.9%, just above Old Quarry at 70.7%, while Central is at 59%. Central is the lowest of the three in both subjects, yet remains above the state: 67% versus 56% in ELA, and 59% versus 40% in math. Lemont Township High School, the only high school listed, is also above the state on its reported ACT subjects, including 80% in ELA versus 50% statewide. Oakwood School has no test scores supplied, and the science scores available are from different grades, so the data do not support a complete achievement ranking of all five schools.

Recent IAR trends differ by school: from 2024–2025 to 2025–2026, Old Quarry improved in both ELA and math, while Central and River Valley declined in math. Across the three schools, the average ELA result rose 1 point and the average math result fell 1 point; in both subjects, the average gap above the state narrowed by 2 points. SchoolDigger ranks Lemont Township High at the 96th percentile, Old Quarry at the 94th and Central at the 77th for 2025–2026. As context, all five schools report free/reduced lunch eligible for 2024–2025, with rates rounding to 15%–20% and an average of 18%; student-teacher ratios range from 15.0:1 to 16.3:1.