#1 Largest Private Schools in Saint Charles, MO
St. Joseph School
Parish school · Grades Pre-K–8
891 students
Saint Charles, MO
B-Overall grade891 students20 students per teacher
2026 lists
Largest Private Schools in Saint Charles, MO
The private schools in Saint Charles, MO with the most students. Top 10 of 10 schools.
#2 Largest Private Schools in Saint Charles, MO
Immanuel Lutheran School
Lutheran (Missouri Synod) school · Grades Pre-K–8
366 students
Saint Charles, MO
B-Overall grade366 students13 students per teacher
#3 Largest Private Schools in Saint Charles, MO
Zion Lutheran School
Lutheran (Missouri Synod) school · Grades Pre-K–8
364 students
Saint Charles, MO
B-Overall grade364 students18 students per teacher
#4 Largest Private Schools in Saint Charles, MO
Seton Regional Catholic School
Parish school · Grades Pre-K–8
248 students
Saint Charles, MO
BOverall grade248 students16 students per teacher
#5 Largest Private Schools in Saint Charles, MO
Duchesne High School
Diocesan school · Grades 9–12
225 students
Saint Charles, MO
A+Overall grade225 students8 students per teacher
#6 Largest Private Schools in Saint Charles, MO
St. Cletus School
Parish school · Grades Pre-K–8
176 students
Saint Charles, MO
A+Overall grade176 students10 students per teacher
#7 Largest Private Schools in Saint Charles, MO
St. John Paul II Preparatory
Independent Catholic school · Grades Pre-K–12
176 students
Saint Charles, MO
B-Overall grade176 students7 students per teacher
#8 Largest Private Schools in Saint Charles, MO
Academy of the Sacred Heart
Independent Catholic school · Grades Pre-K–8
164 students
Saint Charles, MO
A+Overall grade164 students10 students per teacher
#9 Largest Private Schools in Saint Charles, MO
Sts. Joachim & Ann School
Parish school · Grades Pre-K–8
155 students
Saint Charles, MO
BOverall grade155 students12 students per teacher
#10 Largest Private Schools in Saint Charles, MO
Trinity Lutheran School
Lutheran (Missouri Synod) school · Grades K–8
23 students
Saint Charles, MO
AOverall grade23 students7 students per teacher
From official public records, updated October 2026.