#1 Largest Private Schools in O'Fallon, MO
St. Dominic High School
Diocesan school · Grades 9–12
1,087 students
O'Fallon, MO
B-Overall grade1,087 students17 students per teacher
2026 lists
Largest Private Schools in O'Fallon, MO
The private schools in O'Fallon, MO with the most students. Top 5 of 5 schools.
#2 Largest Private Schools in O'Fallon, MO
Christian School District
Christian school (nondenominational) · Grades Pre-K–12
596 students
O'Fallon, MO
B-Overall grade596 students13 students per teacher
#3 Largest Private Schools in O'Fallon, MO
Christian School District
Christian school (nondenominational) · Grades Pre-K–12
596 students
O'Fallon, MO
B-Overall grade596 students12 students per teacher
#4 Largest Private Schools in O'Fallon, MO
Assumption Catholic School
Parish school · Grades Pre-K–8
374 students
O'Fallon, MO
B-Overall grade374 students14 students per teacher
#5 Largest Private Schools in O'Fallon, MO
First Baptist Christian Academy
Baptist school · Grades Pre-K–8
163 students
O'Fallon, MO
B+Overall grade163 students11 students per teacher
From official public records, updated October 2026.