#1 Private Schools with the Smallest Classes in Ada County, 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 Ada County, ID
Private schools in Ada County, ID with the fewest students per teacher (not counting preschools and special education schools). Top 15 of 15 schools.
#2 Private Schools with the Smallest Classes in Ada County, 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 Ada County, 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 Ada County, ID
A Child's Choice Montessori School
Montessori school · Grades Pre-K–6
6.2 students per teacher
Meridian, ID
AOverall grade52 students6 students per teacher
#5 Private Schools with the Smallest Classes in Ada County, ID
Montessori Academy
Montessori school · Grades Pre-K–6
10.3 students per teacher
Eagle, ID
B+Overall grade62 students10 students per teacher
#6 Private Schools with the Smallest Classes in Ada County, 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
#7 Private Schools with the Smallest Classes in Ada County, ID
Calvary Christian School
Christian school (nondenominational) · Grades Pre-K–8
13.2 students per teacher
Boise, ID
BOverall grade223 students13 students per teacher
#8 Private Schools with the Smallest Classes in Ada County, ID
St. Marks Elementary School
Parish school · Grades Pre-K–8
13.7 students per teacher
Boise, ID
AOverall grade323 students14 students per teacher
#9 Private Schools with the Smallest Classes in Ada County, ID
Sacred Heart Catholic School
Diocesan school · Grades Pre-K–8
15 students per teacher
Boise, ID
BOverall grade195 students15 students per teacher
#10 Private Schools with the Smallest Classes in Ada County, ID
Calvary Meridian Prep Academy
Christian school (nondenominational) · Grades K–10
15 students per teacher
Meridian, ID
BOverall grade185 students15 students per teacher
#11 Private Schools with the Smallest Classes in Ada County, 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
#12 Private Schools with the Smallest Classes in Ada County, ID
Cole Valley Christian Schools-Secondary
Christian school (nondenominational) · Grades Pre-K–12
15.8 students per teacher
Meridian, ID
B-Overall grade1,263 students16 students per teacher
#13 Private Schools with the Smallest Classes in Ada County, ID
Bishop Kelly High School
Diocesan school · Grades 9–12
16 students per teacher
Boise, ID
BOverall grade967 students16 students per teacher
#14 Private Schools with the Smallest Classes in Ada County, ID
St. Ignatius Catholic School
Diocesan school · Grades Pre-K–8
17.8 students per teacher
Meridian, ID
B-Overall grade428 students18 students per teacher
#15 Private Schools with the Smallest Classes in Ada County, 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.