#1 Private Schools with the Smallest Classes in Ontario, CA
Orion International Academy
Independent school · Grades K–12
10.3 students per teacher
Ontario, CA
BOverall grade112 students10 students per teacher
2026 lists
Private Schools with the Smallest Classes in Ontario, CA
Private schools in Ontario, CA with the fewest students per teacher (not counting preschools and special education schools). Top 7 of 7 schools.
#2 Private Schools with the Smallest Classes in Ontario, CA
The Good Shepherd Academy
Independent school · Grades 1–8
10.4 students per teacher
Ontario, CA
B+Overall grade52 students10 students per teacher
#3 Private Schools with the Smallest Classes in Ontario, CA
Montecito Baptist School
Baptist school · Grades K–12
11.3 students per teacher
Ontario, CA
B+Overall grade96 students11 students per teacher
#4 Private Schools with the Smallest Classes in Ontario, CA
San Antonio Christian School
Seventh-day Adventist school · Grades K–8
15 students per teacher
Ontario, CA
B+Overall grade60 students15 students per teacher
#5 Private Schools with the Smallest Classes in Ontario, CA
Ontario Christian School
Christian school (nondenominational) · Grades Pre-K–12
17 students per teacher
Ontario, CA
B+Overall grade1,438 students17 students per teacher
#6 Private Schools with the Smallest Classes in Ontario, CA
Wesley College Preparatory School
Christian school (nondenominational) · Grades 9–12
21.4 students per teacher
Ontario, CA
BOverall grade150 students21 students per teacher
#7 Private Schools with the Smallest Classes in Ontario, CA
St. George Parish School
Parish school · Grades K–8
22.1 students per teacher
Ontario, CA
BOverall grade316 students22 students per teacher
From official public records, updated October 2026.