#1 Largest Private Schools in St. Charles County, 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 St. Charles County, MO
The private schools in St. Charles County, MO with the most students. Top 27 of 27 schools.
#2 Largest Private Schools in St. Charles County, MO
St. Joseph School
Parish school · Grades Pre-K–8
891 students
Saint Charles, MO
B-Overall grade891 students20 students per teacher
#3 Largest Private Schools in St. Charles County, MO
Immaculate Conception School
Parish school · Grades Pre-K–8
715 students
Dardenne Prairie, MO
B-Overall grade715 students19 students per teacher
#4 Largest Private Schools in St. Charles County, MO
Christian School District
Christian school (nondenominational) · Grades Pre-K–12
596 students
O'Fallon, MO
B-Overall grade596 students13 students per teacher
#5 Largest Private Schools in St. Charles County, MO
Christian School District
Christian school (nondenominational) · Grades Pre-K–12
596 students
O'Fallon, MO
B-Overall grade596 students12 students per teacher
#6 Largest Private Schools in St. Charles County, MO
Lutheran High School of St. Charles County
Lutheran (Missouri Synod) school · Grades 9–12
460 students
Saint Peters, MO
BOverall grade460 students15 students per teacher
#7 Largest Private Schools in St. Charles County, MO
St. Patrick School
Diocesan school · Grades Pre-K–8
436 students
Wentzville, MO
B-Overall grade436 students17 students per teacher
#8 Largest Private Schools in St. Charles County, MO
Immanuel Lutheran School
Lutheran (Missouri Synod) school · Grades K–8
385 students
Wentzville, MO
B-Overall grade385 students15 students per teacher
#9 Largest Private Schools in St. Charles County, MO
Assumption Catholic School
Parish school · Grades Pre-K–8
374 students
O'Fallon, MO
B-Overall grade374 students14 students per teacher
#10 Largest Private Schools in St. Charles County, MO
Immanuel Lutheran School
Lutheran (Missouri Synod) school · Grades Pre-K–8
366 students
Saint Charles, MO
B-Overall grade366 students13 students per teacher
#11 Largest Private Schools in St. Charles County, MO
Zion Lutheran School
Lutheran (Missouri Synod) school · Grades Pre-K–8
364 students
Saint Charles, MO
B-Overall grade364 students18 students per teacher
#12 Largest Private Schools in St. Charles County, MO
St. Theodore School
Parish school · Grades Pre-K–8
260 students
Wentzville, MO
B-Overall grade260 students16 students per teacher
#13 Largest Private Schools in St. Charles County, MO
Seton Regional Catholic School
Parish school · Grades Pre-K–8
248 students
Saint Charles, MO
BOverall grade248 students16 students per teacher
#14 Largest Private Schools in St. Charles County, MO
Duchesne High School
Diocesan school · Grades 9–12
225 students
Saint Charles, MO
A+Overall grade225 students8 students per teacher
#15 Largest Private Schools in St. Charles County, MO
St. Paul Elementary School
Parish school · Grades Pre-K–8
222 students
Saint Paul, MO
B-Overall grade222 students19 students per teacher
#16 Largest Private Schools in St. Charles County, MO
St. Cletus School
Parish school · Grades Pre-K–8
176 students
Saint Charles, MO
A+Overall grade176 students10 students per teacher
#17 Largest Private Schools in St. Charles County, 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
#18 Largest Private Schools in St. Charles County, 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
#19 Largest Private Schools in St. Charles County, MO
First Baptist Christian Academy
Baptist school · Grades Pre-K–8
163 students
O'Fallon, MO
B+Overall grade163 students11 students per teacher
#20 Largest Private Schools in St. Charles County, MO
Sts. Joachim & Ann School
Parish school · Grades Pre-K–8
155 students
Saint Charles, MO
BOverall grade155 students12 students per teacher
#21 Largest Private Schools in St. Charles County, MO
Child of God Lutheran School
Lutheran (Missouri Synod) school · Grades Pre-K–8
139 students
Saint Peters, MO
BOverall grade139 students13 students per teacher
#22 Largest Private Schools in St. Charles County, MO
All Saints School
Parish school · Grades Pre-K–8
125 students
Saint Peters, MO
A+Overall grade125 students7 students per teacher
#23 Largest Private Schools in St. Charles County, MO
Andrews Academy
Independent school · Grades K–8
123 students
Lake Saint Louis, MO
B+Overall grade123 students5 students per teacher
#24 Largest Private Schools in St. Charles County, MO
St. Joseph School-Josephville
Diocesan school · Grades Pre-K–8
79 students
Wentzville, MO
A-Overall grade79 students9 students per teacher
From official public records, updated October 2026.