#1 Private Schools with the Smallest Classes in Boise, ID
Riverstone International School
Independent school · Grades Pre-K–12
5 students per teacher
Boise, ID
A+Overall grade349 students5 students per teacher
2026 lists
Private Schools with the Smallest Classes in Boise, ID
Private schools in Boise, ID with the fewest students per teacher (not counting preschools and special education schools). Top 10 of 10 schools.
#2 Private Schools with the Smallest Classes in Boise, ID
St. Marys School
Diocesan school · Grades Pre-K–8
6 students per teacher
Boise, ID
A+Overall grade109 students6 students per teacher
#3 Private Schools with the Smallest Classes in Boise, ID
Boise State University Trio Upward Bound
Alternative school · Grades 9–11
6.2 students per teacher
Boise, ID
A-Overall grade80 students6 students per teacher
#4 Private Schools with the Smallest Classes in Boise, ID
Boise Valley Adventist School
Seventh-day Adventist school · Grades Pre-K–8
12.9 students per teacher
Boise, ID
BOverall grade75 students13 students per teacher
#5 Private Schools with the Smallest Classes in Boise, ID
Calvary Christian School
Christian school (nondenominational) · Grades Pre-K–8
13.2 students per teacher
Boise, ID
BOverall grade223 students13 students per teacher
#6 Private Schools with the Smallest Classes in Boise, ID
St. Marks Elementary School
Parish school · Grades Pre-K–8
13.7 students per teacher
Boise, ID
AOverall grade323 students14 students per teacher
#7 Private Schools with the Smallest Classes in Boise, ID
Sacred Heart Catholic School
Diocesan school · Grades Pre-K–8
15 students per teacher
Boise, ID
BOverall grade195 students15 students per teacher
#8 Private Schools with the Smallest Classes in Boise, ID
St. Joseph's Catholic School
Diocesan school · Grades K–8
15.3 students per teacher
Boise, ID
B+Overall grade367 students15 students per teacher
#9 Private Schools with the Smallest Classes in Boise, ID
Bishop Kelly High School
Diocesan school · Grades 9–12
16 students per teacher
Boise, ID
BOverall grade967 students16 students per teacher
#10 Private Schools with the Smallest Classes in Boise, ID
One Stone
Independent school · Grades 9–12
36.2 students per teacher
Boise, ID
BOverall grade87 students36 students per teacher
From official public records, updated October 2026.