O'Fallon Township High School is a public secondary school in O'Fallon, Illinois. As of 2023, it is the second largest public high school in Illinois by enrollment outside of the Chicago area.
Serving 2,540 students in grades 9-12, O Fallon High School ranks in the top 30% of all schools in Illinois for overall test scores (math proficiency is top 30%, and reading proficiency is top 30%).
The percentage of students achieving proficiency in math is 36% (which is higher than the Illinois state average of 27%). The percentage of students achieving proficiency in reading/language arts is 42% (which is higher than the Illinois state average of 30%).
The student-teacher ratio of 16:1 is higher than the Illinois state level of 13:1.
Minority enrollment is 41% of the student body (majority Black), which is lower than the Illinois state average of 55% (majority Hispanic).
Quick Facts (2026)
- Grades: 9-12
- Enrollment: 2,540 students
- Student-Teacher Ratio: 16:1
- Minority Enrollment: 41%
- Graduation Rate: 94% (Top 20% in IL)
- Overall Testing Rank: Top 30%
- Math Proficiency: 36% (Top 30%)
- Reading Proficiency: 42% (Top 30%)
- Science Proficiency: 59% (Top 50%)
- Attendance Zone: O'Fallon High School serves the entire district of O'Fallon, IL, covering an area of approximately 49.4 square miles. Most students typically have a drive of 10 to 12 minutes to reach the school, with the furthest edge of the attendance zone being about 6.4 miles away.
- Source: National Center for Education Statistics (NCES), IL Dept. of Education
Top Rankings
O Fallon High School ranks among the top 20% of public schools in Illinois for:
Category
Attribute
Most improved public schools
Graduation Rate
School Overview
O Fallon High School's student population of 2,540 students has stayed relatively flat over five school years.
The teacher population of 156 teachers has grown by 14% over five school years.
Grades Offered
Grades 9-12
Total Students
2,540 students
Total Classroom Teachers
156 teachers
Year Founded
1901
Colors
Blue, Gold
School Calendar
Campus Size
50 acres
School Rankings
O Fallon High School ranks within the top 30% of all 3,542 schools in Illinois (based off of combined math and reading proficiency testing data).
The diversity score of O Fallon High School is 0.60, which is less than the diversity score at state average of 0.70. The school's diversity has stayed relatively flat over five school years.
Overall Testing Rank
#823 out of 3542 schools
(Top 30%)
(Top 30%)
Math Test Scores (% Proficient)
36%
27%
Reading/Language Arts Test Scores (% Proficient)
42%
30%
Science Test Scores (% Proficient)
59%
50%
Student-Teacher Ratio
16:1
13:1
American Indian
n/a
n/a
Asian
3%
6%
Hispanic
8%
29%
Black
20%
16%
White
59%
45%
Hawaiian
n/a
n/a
Two or more races
10%
4%
All Ethnic Groups
Graduation Rate
94%
87%
Chronically Absent Students
(22-23)24.5%
29.7%
Eligible for Free Lunch
16%
43%
Eligible for Reduced Lunch
7%
4%
School Statewide Testing
School District Name
Source: National Center for Education Statistics (NCES), IL Dept. of Education
School Notes
- School Mascot: Panther
Frequently Asked Questions
What is O Fallon High School's ranking?
O Fallon High School is ranked #823 out of 3,542 schools, which ranks it among the top 30% of public schools in Illinois.
What schools are O Fallon High School often compared to?
O Fallon High Schoolis often viewed alongside schools like Mascoutah High School, Belleville High School-east by visitors of our site.
What percent of students have achieved state testing proficiency in math and reading?
36% of students have achieved math proficiency (compared to the 27% IL state average), while 42% of students have achieved reading proficiency (compared to the 30% IL state average).
What is the graduation rate of O Fallon High School?
The graduation rate of O Fallon High School is 94%, which is higher than the Illinois state average of 87%.
How many students attend O Fallon High School?
2,540 students attend O Fallon High School.
What is the racial composition of the student body?
59% of O Fallon High School students are White, 20% of students are Black, 10% of students are Two or more races, 8% of students are Hispanic, and 3% of students are Asian.
What is the student-teacher ratio of O Fallon High School?
O Fallon High School has a student ration of 16:1, which is higher than the Illinois state average of 13:1.
What grades does O Fallon High School offer ?
O Fallon High School offers enrollment in grades 9-12
What school district is O Fallon High School part of?
O Fallon High School is part of O Fallon TWP HSD 203 School District.
School Reviews
5 10/10/2025
I am currently a freshmen at O'Fallon Township High School after I moved from New York. I was originally goig to move to St. Louis but my mother found out what a great school it was and couldn't resist. Academic Programs are excellent and their extracurricular activities are amazing! Everybody comes out to the school sports and attend the music concerts. In the back of the school handbook there are pages filled with different types of clubs and activities. The level of parent involvement is awesome! I recently went to a girl's lacrosse game and there was a team of mothers selling candy and snacks to help raise money for the girls.
5 10/10/2025
The teachers are, for the most part, professional and consistent. Extracurricular activities are vastly upheld and the men and women who coordinate them work very hard. This school is a small-town high school, obviously, yet everyone finds their niche. Administration is slightly inert but the guidance counselors are excellent. Sports are great; the music programs are just as great, if not better.
Do not forget that the teachers of the Milburn (freshman) campus are trained and experienced in high school education. So, they will not be keeping your child in middle school standards, although the building is quite detached from the rest of the high school. They will be treated as high schoolers. Also, true maturity is not based on imitating elders (the sophomores, juniors, and especially seniors.) Exposure to the students of those grades is not absolutely necessary. Allow your child to rise above the rest, through their own experience, and it will stick longer than impression of emotional aging that is created just for peer approval.
Review O Fallon High School. Reviews should be a few sentences in length. Please include any comments on:
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