#1 Largest Private Schools in McHenry County, IL
Marian Central Catholic High School
Diocesan school · Grades 9–12
294 students
Woodstock, IL
A+Overall grade294 students12 students per teacher
2026 lists
Largest Private Schools in McHenry County, IL
The private schools in McHenry County, IL with the most students. Top 14 of 14 schools.
#2 Largest Private Schools in McHenry County, IL
Trinity Oaks Christian Academy
Christian school (nondenominational) · Grades Pre-K–12
268 students
Cary, IL
BOverall grade268 students12 students per teacher
#3 Largest Private Schools in McHenry County, IL
Immanuel Lutheran School
Lutheran (Missouri Synod) school · Grades Pre-K–8
232 students
Crystal Lake, IL
B-Overall grade232 students13 students per teacher
#4 Largest Private Schools in McHenry County, IL
Montini Catholic School
Diocesan school · Grades Pre-K–8
196 students
McHenry, IL
A+Overall grade196 students11 students per teacher
#5 Largest Private Schools in McHenry County, IL
Zion Lutheran School
Lutheran (Missouri Synod) school · Grades Pre-K–8
191 students
Marengo, IL
B-Overall grade191 students15 students per teacher
#6 Largest Private Schools in McHenry County, IL
SS Peter & Paul School
Parish school · Grades Pre-K–8
167 students
Cary, IL
A+Overall grade167 students10 students per teacher
#7 Largest Private Schools in McHenry County, IL
St. Margaret Mary Catholic School
Diocesan school · Grades Pre-K–8
166 students
Algonquin, IL
BOverall grade166 students17 students per teacher
#8 Largest Private Schools in McHenry County, IL
St. Thomas the Apostle School
Diocesan school · Grades Pre-K–8
164 students
Crystal Lake, IL
A+Overall grade164 students9 students per teacher
#9 Largest Private Schools in McHenry County, IL
St. Mary Catholic School
Diocesan school · Grades Pre-K–8
125 students
Woodstock, IL
A+Overall grade125 students10 students per teacher
#10 Largest Private Schools in McHenry County, IL
Crystal Lake Montessori School
Montessori school · Grades Pre-K–8
76 students
Woodstock, IL
A+Overall grade76 students3 students per teacher
#11 Largest Private Schools in McHenry County, IL
St. John the Baptist Catholic School
Diocesan school · Grades Pre-K–8
54 students
Johnsburg, IL
A+Overall grade54 students5 students per teacher
#12 Largest Private Schools in McHenry County, IL
Allendale - Linc
Special education school · Grades 5–12
25 students
Woodstock, IL
B+Overall grade25 students8 students per teacher
#13 Largest Private Schools in McHenry County, IL
Montessori Pathways School
Montessori school · Grades Pre-K–6
22 students
Crystal Lake, IL
A-Overall grade22 students4 students per teacher
#14 Largest Private Schools in McHenry County, IL
Notre Dame Academy
Independent Catholic school · Grades K–12
21 students
Marengo, IL
AOverall grade21 students2 students per teacher
From official public records, updated October 2026.