#49 Largest Private Schools in Illinois
Sacred Heart Griffin High School
Independent Catholic school · Grades 9–12
526 students
Springfield, IL
B-Overall grade526 students16 students per teacher
2026 lists
Largest Private Schools in Illinois
The private schools in Illinois with the most students. Top 50 of 797 schools.
#50 Largest Private Schools in Illinois
St. Francis Xavier School
Parish school · Grades Pre-K–8
520 students
Wilmette, IL
A+Overall grade520 students6 students per teacher
From official public records, updated October 2026.