#1 Largest Private Schools in Castro Valley, CA
Redwood Christian Elementary School
Christian school (nondenominational) · Grades K–5
268 students
Castro Valley, CA
BOverall grade268 students16 students per teacher
2026 lists
Largest Private Schools in Castro Valley, CA
The private schools in Castro Valley, CA with the most students. Top 5 of 5 schools.
#2 Largest Private Schools in Castro Valley, CA
Our Lady of Grace Catholic School
Diocesan school · Grades K–8
166 students
Castro Valley, CA
A+Overall grade166 students10 students per teacher
#3 Largest Private Schools in Castro Valley, CA
Mission Hills School
Independent school · Grades K–5
126 students
Castro Valley, CA
B-Overall grade126 students18 students per teacher
#4 Largest Private Schools in Castro Valley, CA
Anchor Education, INC. DBA One School Global-San F
Christian school (nondenominational) · Grades 3–11
30 students
Castro Valley, CA
AOverall grade30 students8 students per teacher
#5 Largest Private Schools in Castro Valley, CA
One School Global-San Francisco Campus
Independent school · Grades 3–11
30 students
Castro Valley, CA
B+Overall grade30 students7 students per teacher
From official public records, updated October 2026.