#1 Largest Private Schools in Sonoma County, CA
Cardinal Newman High School
Diocesan school · Grades 9–12
550 students
Santa Rosa, CA
A+Overall grade550 students11 students per teacher
2026 lists
Largest Private Schools in Sonoma County, CA
The private schools in Sonoma County, CA with the most students. Top 32 of 32 schools.
#2 Largest Private Schools in Sonoma County, CA
Sonoma Academy
Independent school · Grades 9–12
340 students
Santa Rosa, CA
BOverall grade340 students
#3 Largest Private Schools in Sonoma County, CA
St. Rose Elementary School
Parish school · Grades Pre-K–8
305 students
Santa Rosa, CA
BOverall grade305 students22 students per teacher
#4 Largest Private Schools in Sonoma County, CA
St. John the Baptist Catholic School
Diocesan school · Grades K–8
293 students
Healdsburg, CA
BOverall grade293 students22 students per teacher
#5 Largest Private Schools in Sonoma County, CA
Sonoma Country Day School
Independent school · Grades Pre-K–8
280 students
Santa Rosa, CA
A+Overall grade280 students7 students per teacher
#6 Largest Private Schools in Sonoma County, CA
The Healdsburg School
Independent school · Grades K–8
234 students
Healdsburg, CA
B+Overall grade234 students8 students per teacher
#7 Largest Private Schools in Sonoma County, CA
Summerfield Waldorf School and Farm
Independent school · Grades Pre-K–12
225 students
Santa Rosa, CA
BOverall grade225 students9 students per teacher
#8 Largest Private Schools in Sonoma County, CA
St. Francis Solano School
Parish school · Grades K–8
192 students
Sonoma, CA
A+Overall grade192 students13 students per teacher
#9 Largest Private Schools in Sonoma County, CA
St. Vincent De Paul Elementary School
Parish school · Grades K–8
192 students
Petaluma, CA
B+Overall grade192 students18 students per teacher
#10 Largest Private Schools in Sonoma County, CA
Grace Christian Academy
Christian school (nondenominational) · Grades K–12
189 students
Santa Rosa, CA
B-Overall grade189 students14 students per teacher
#11 Largest Private Schools in Sonoma County, CA
Victory Christian Academy
Christian school (nondenominational) · Grades K–12
175 students
Santa Rosa, CA
B+Overall grade175 students12 students per teacher
#12 Largest Private Schools in Sonoma County, CA
Harvest Christian School
Christian school (nondenominational) · Grades Pre-K–8
172 students
Petaluma, CA
BOverall grade172 students15 students per teacher
#13 Largest Private Schools in Sonoma County, CA
St. Vincent De Paul High School
Parish school · Grades 9–12
169 students
Petaluma, CA
A+Overall grade169 students9 students per teacher
#14 Largest Private Schools in Sonoma County, CA
The Presentation School
Independent Catholic school · Grades K–8
158 students
Sonoma, CA
A+Overall grade158 students8 students per teacher
#15 Largest Private Schools in Sonoma County, CA
Anova Center for Education Sonoma County
Special education school · Grades 2–12
133 students
Santa Rosa, CA
BOverall grade133 students11 students per teacher
#16 Largest Private Schools in Sonoma County, CA
Rio Lindo Adventist Academy
Seventh-day Adventist school · Grades 9–12
113 students
Healdsburg, CA
A+Overall grade113 students7 students per teacher
#17 Largest Private Schools in Sonoma County, CA
The Spring Hill School
Independent school · Grades Pre-K–8
109 students
Petaluma, CA
A+Overall grade109 students5 students per teacher
#18 Largest Private Schools in Sonoma County, CA
Redwood Adventist Academy
Seventh-day Adventist school · Grades K–8
98 students
Santa Rosa, CA
AOverall grade98 students14 students per teacher
#19 Largest Private Schools in Sonoma County, CA
St. Eugene's Cathedral School
Independent Catholic school · Grades K–8
87 students
Santa Rosa, CA
B+Overall grade87 students17 students per teacher
#20 Largest Private Schools in Sonoma County, CA
Pleasant Hill Christian School
Christian school (nondenominational) · Grades K–6
71 students
Sebastopol, CA
B+Overall grade71 students10 students per teacher
#21 Largest Private Schools in Sonoma County, CA
Quest Forward High School
Independent school · Grades 9–12
62 students
Santa Rosa, CA
B+Overall grade62 students7 students per teacher
#22 Largest Private Schools in Sonoma County, CA
College Oak Montessori School
Montessori school · Ungraded
62 students
Santa Rosa, CA
BOverall grade62 students31 students per teacher
#23 Largest Private Schools in Sonoma County, CA
Greenacre Homes
Special education school · Grades 2–12
57 students
Sebastopol, CA
A-Overall gradeAll boys57 students8 students per teacher
#24 Largest Private Schools in Sonoma County, CA
Cypress School
Special education school · Grades 8–12
43 students
Petaluma, CA
B+Overall grade43 students9 students per teacher
From official public records, updated October 2026.