#1 Largest Private Schools in Dupage County, IL
Timothy Christian Schools
Christian school (nondenominational) · Grades Pre-K–12
1,194 students
Elmhurst, IL
B+Overall grade1,194 students18 students per teacher
2026 lists
Largest Private Schools in Dupage County, IL
The private schools in Dupage County, IL with the most students. Top 50 of 64 schools.
#2 Largest Private Schools in Dupage County, IL
St. Francis High School
Independent Catholic school · Grades 9–12
703 students
Wheaton, IL
AOverall grade703 students13 students per teacher
#3 Largest Private Schools in Dupage County, IL
Wheaton Christian Grammar School
Christian school (nondenominational) · Grades K–8
646 students
Winfield, IL
BOverall grade646 students16 students per teacher
#4 Largest Private Schools in Dupage County, IL
Islamic Foundation School
Islamic school · Grades Pre-K–12
633 students
Villa Park, IL
B+Overall grade633 students14 students per teacher
#5 Largest Private Schools in Dupage County, IL
College Preparatory School of America
Islamic school · Grades Pre-K–12
602 students
Lombard, IL
A+Overall grade602 students13 students per teacher
#6 Largest Private Schools in Dupage County, IL
St. Petronille School
Diocesan school · Grades Pre-K–8
493 students
Glen Ellyn, IL
B-Overall grade493 students18 students per teacher
#7 Largest Private Schools in Dupage County, IL
Immaculate Conception Grade School
Diocesan school · Grades Pre-K–8
468 students
Elmhurst, IL
B-Overall grade468 students18 students per teacher
#8 Largest Private Schools in Dupage County, IL
Saints Peter & Paul School
Diocesan school · Grades Pre-K–8
435 students
Naperville, IL
B-Overall grade435 students17 students per teacher
#9 Largest Private Schools in Dupage County, IL
St. Mary of Gostyn Catholic School
Parish school · Grades Pre-K–8
419 students
Downers Grove, IL
BOverall grade419 students15 students per teacher
#10 Largest Private Schools in Dupage County, IL
All Saints Catholic Academy
Parish school · Grades Pre-K–8
414 students
Naperville, IL
A-Overall grade414 students14 students per teacher
#11 Largest Private Schools in Dupage County, IL
St. Joseph
Diocesan school · Grades Pre-K–8
371 students
Downers Grove, IL
BOverall grade371 students16 students per teacher
#12 Largest Private Schools in Dupage County, IL
Ic Catholic Prep
Diocesan school · Grades 9–12
371 students
Elmhurst, IL
A+Overall grade371 students9 students per teacher
#13 Largest Private Schools in Dupage County, IL
St. Walter School
Parish school · Grades Pre-K–8
341 students
Roselle, IL
A+Overall grade341 students8 students per teacher
#14 Largest Private Schools in Dupage County, IL
St. Joan of Arc
Parish school · Grades Pre-K–8
308 students
Lisle, IL
B+Overall grade308 students14 students per teacher
#15 Largest Private Schools in Dupage County, IL
St. Pius X Elementary School
Parish school · Grades Pre-K–8
300 students
Lombard, IL
B+Overall grade300 students14 students per teacher
#16 Largest Private Schools in Dupage County, IL
Avery Coonley School
Independent school · Grades Pre-K–8
290 students
Downers Grove, IL
AOverall grade290 students7 students per teacher
#17 Largest Private Schools in Dupage County, IL
Calvary Christian School
Christian school (nondenominational) · Grades Pre-K–8
257 students
Naperville, IL
AOverall grade257 students10 students per teacher
#18 Largest Private Schools in Dupage County, IL
St. Raphael Catholic School
Diocesan school · Grades Pre-K–8
247 students
Naperville, IL
A-Overall grade247 students13 students per teacher
#19 Largest Private Schools in Dupage County, IL
St. Philip the Apostle School
Diocesan school · Grades Pre-K–8
237 students
Addison, IL
BOverall grade237 students17 students per teacher
#20 Largest Private Schools in Dupage County, IL
St. Scholastica Parish School
Parish school · Grades K–8
203 students
Woodridge, IL
BOverall grade203 students17 students per teacher
#21 Largest Private Schools in Dupage County, IL
St. Isidore School
Diocesan school · Grades Pre-K–8
189 students
Bloomingdale, IL
B+Overall grade189 students14 students per teacher
#22 Largest Private Schools in Dupage County, IL
St. John the Baptist Catholic School
Diocesan school · Grades Pre-K–8
177 students
Winfield, IL
B-Overall grade177 students16 students per teacher
#23 Largest Private Schools in Dupage County, IL
Bethany Lutheran Church and School
Lutheran (Missouri Synod) school · Grades Pre-K–8
165 students
Naperville, IL
BOverall grade165 students12 students per teacher
#24 Largest Private Schools in Dupage County, IL
St. James the Apostle School
Parish school · Grades Pre-K–8
163 students
Glen Ellyn, IL
B+Overall grade163 students13 students per teacher
From official public records, updated October 2026.