#1 Largest Private Schools in Illinois
American School
Alternative school · Grades 6–12
5,049 students
Lansing, IL
B-Overall grade5,049 students
2026 lists
Largest Private Schools in Illinois
The private schools in Illinois with the most students. Top 50 of 797 schools.
#2 Largest Private Schools in Illinois
Loyola Academy
Independent Catholic school · Grades 9–12
1,947 students
Wilmette, IL
A+Overall grade1,947 students11 students per teacher
#3 Largest Private Schools in Illinois
Univ of Chicago Lab School
Independent school · Grades Pre-K–12
1,946 students
Chicago, IL
A+Overall grade1,946 students8 students per teacher
#4 Largest Private Schools in Illinois
St. Ignatius College Prep
Independent Catholic school · Grades 9–12
1,492 students
Chicago, IL
B+Overall grade1,492 students16 students per teacher
#5 Largest Private Schools in Illinois
Depaul College Prep
Independent Catholic school · Grades 9–12
1,245 students
Chicago, IL
A+Overall grade1,245 students11 students per teacher
#6 Largest Private Schools in Illinois
Timothy Christian Schools
Christian school (nondenominational) · Grades Pre-K–12
1,194 students
Elmhurst, IL
B+Overall grade1,194 students18 students per teacher
#7 Largest Private Schools in Illinois
St. Laurence H.S.
Independent Catholic school · Grades 9–12
1,030 students
Burbank, IL
B+Overall grade1,030 students16 students per teacher
#8 Largest Private Schools in Illinois
Fenwick High School
Parish school · Grades 9–12
1,024 students
Oak Park, IL
A+Overall grade1,024 students12 students per teacher
#9 Largest Private Schools in Illinois
Joan Dachs Bais Yaakov Elementary School
Jewish day school · Grades Pre-K–8
844 students
Chicago, IL
B-Overall gradeAll girls844 students15 students per teacher
#10 Largest Private Schools in Illinois
Joan Dachs Bais Yaakov Elementary School
Jewish day school · Grades K–8
844 students
Chicago, IL
B-Overall gradeAll girls844 students12 students per teacher
#11 Largest Private Schools in Illinois
Bishop McNamara Catholic School
Diocesan school · Grades Pre-K–12
807 students
Kankakee, IL
B-Overall grade807 students16 students per teacher
#12 Largest Private Schools in Illinois
Latin School of Chicago Upper
Independent school · Grades 5–12
806 students
Chicago, IL
BOverall grade806 students11 students per teacher
#13 Largest Private Schools in Illinois
Schaumburg Christian School
Baptist school · Grades Pre-K–12
804 students
Schaumburg, IL
BOverall grade804 students17 students per teacher
#14 Largest Private Schools in Illinois
Nazareth Academy
Independent Catholic school · Grades 9–12
800 students
La Grange Park, IL
A-Overall grade800 students16 students per teacher
#15 Largest Private Schools in Illinois
Marian Catholic High School
Independent Catholic school · Grades 8–12
797 students
Chicago Heights, IL
B+Overall grade797 students15 students per teacher
#16 Largest Private Schools in Illinois
Mother McAuley Liberal Arts High School
Independent Catholic school · Grades 9–12
794 students
Chicago, IL
AOverall gradeAll girls794 students13 students per teacher
#17 Largest Private Schools in Illinois
De La Salle Institute - Institute Campus
Independent Catholic school · Grades 9–12
765 students
Chicago, IL
A-Overall grade765 students16 students per teacher
#18 Largest Private Schools in Illinois
MCC Academy-Elementary
Islamic school · Grades Pre-K–12
760 students
Skokie, IL
B+Overall grade760 students9 students per teacher
#19 Largest Private Schools in Illinois
Universal School
Islamic school · Grades Pre-K–12
757 students
Bridgeview, IL
BOverall grade757 students14 students per teacher
#20 Largest Private Schools in Illinois
Southwest Chicago Christian Schools Associaiton
Christian school (nondenominational) · Grades Pre-K–12
756 students
Palos Heights, IL
BOverall grade756 students14 students per teacher
#21 Largest Private Schools in Illinois
Providence Catholic High School
Diocesan school · Grades 9–12
754 students
New Lenox, IL
B-Overall grade754 students17 students per teacher
#22 Largest Private Schools in Illinois
Frances Xavier Warde School
Independent Catholic school · Grades Pre-K–8
745 students
Chicago, IL
A+Overall grade745 students6 students per teacher
#23 Largest Private Schools in Illinois
MCC Academy College Prep
Islamic school · Grades Pre-K–12
736 students
Morton Grove, IL
B+Overall grade736 students9 students per teacher
#24 Largest Private Schools in Illinois
St. Francis High School
Independent Catholic school · Grades 9–12
703 students
Wheaton, IL
AOverall grade703 students13 students per teacher
From official public records, updated October 2026.