#1 Largest Private Schools in Multnomah County, OR
Central Catholic High School
Diocesan school · Grades 9–12
865 students
Portland, OR
B+Overall grade865 students15 students per teacher
2026 lists
Largest Private Schools in Multnomah County, OR
The private schools in Multnomah County, OR with the most students. Top 49 of 49 schools.
#2 Largest Private Schools in Multnomah County, OR
Portland Christian Schools
Christian school (nondenominational) · Grades Pre-K–12
628 students
Portland, OR
AOverall grade628 students14 students per teacher
#3 Largest Private Schools in Multnomah County, OR
St. Marys Academy
Independent Catholic school · Grades 9–12
606 students
Portland, OR
A-Overall gradeAll girls606 students12 students per teacher
#4 Largest Private Schools in Multnomah County, OR
Rosemary Anderson High School/Portland Oic
Alternative school · Grades 6–12
326 students
Portland, OR
B-Overall grade326 students14 students per teacher
#5 Largest Private Schools in Multnomah County, OR
Columbia Christian Schools
Church of Christ school · Grades Pre-K–12
322 students
Portland, OR
B+Overall grade322 students13 students per teacher
#6 Largest Private Schools in Multnomah County, OR
Portland Christian Elementary School
Christian school (nondenominational) · Grades Pre-K–5
322 students
Portland, OR
B-Overall grade322 students17 students per teacher
#7 Largest Private Schools in Multnomah County, OR
West Hills Christian School
Christian school (nondenominational) · Grades K–8
322 students
Portland, OR
BOverall grade322 students13 students per teacher
#8 Largest Private Schools in Multnomah County, OR
Portland Adventist Elementary School
Seventh-day Adventist school · Grades Pre-K–8
292 students
Gresham, OR
BOverall grade292 students17 students per teacher
#9 Largest Private Schools in Multnomah County, OR
Open Door Christian Academy
Baptist school · Grades Pre-K–12
291 students
Troutdale, OR
B-Overall grade291 students20 students per teacher
#10 Largest Private Schools in Multnomah County, OR
International School of Portland
Independent school · Grades Pre-K–5
290 students
Portland, OR
A+Overall grade290 students8 students per teacher
#11 Largest Private Schools in Multnomah County, OR
The Madeleine Elementary School
Diocesan school · Grades K–8
256 students
Portland, OR
BOverall grade256 students18 students per teacher
#12 Largest Private Schools in Multnomah County, OR
Holy Redeemer Catholic School
Diocesan school · Grades Pre-K–8
236 students
Portland, OR
A-Overall grade236 students16 students per teacher
#13 Largest Private Schools in Multnomah County, OR
St. Clare School
Diocesan school · Grades K–8
228 students
Portland, OR
BOverall grade228 students15 students per teacher
#14 Largest Private Schools in Multnomah County, OR
Franciscan Montessori Earth School
Independent Catholic school · Grades Pre-K–8
228 students
Portland, OR
B+Overall grade228 students16 students per teacher
#15 Largest Private Schools in Multnomah County, OR
De La Salle North Catholic High School
Independent Catholic school · Grades 9–12
220 students
Portland, OR
AOverall grade220 students12 students per teacher
#16 Largest Private Schools in Multnomah County, OR
Holy Cross Catholic School
Parish school · Grades Pre-K–8
215 students
Portland, OR
A+Overall grade215 students14 students per teacher
#17 Largest Private Schools in Multnomah County, OR
Cedarwood Waldorf School
Independent school · Grades Pre-K–8
215 students
Portland, OR
BOverall grade215 students11 students per teacher
#18 Largest Private Schools in Multnomah County, OR
St. John Fisher
Parish school · Grades Pre-K–8
204 students
Portland, OR
A+Overall grade204 students9 students per teacher
#19 Largest Private Schools in Multnomah County, OR
St. Ignatius School
Diocesan school · Grades Pre-K–8
196 students
Portland, OR
AOverall grade196 students15 students per teacher
#20 Largest Private Schools in Multnomah County, OR
St. Therese Catholic School
Diocesan school · Grades Pre-K–8
195 students
Portland, OR
B+Overall grade195 students18 students per teacher
#21 Largest Private Schools in Multnomah County, OR
St. Rose School
Parish school · Grades Pre-K–8
194 students
Portland, OR
A+Overall grade194 students9 students per teacher
#22 Largest Private Schools in Multnomah County, OR
St. Thomas More School
Diocesan school · Grades K–8
193 students
Portland, OR
AOverall grade193 students12 students per teacher
#23 Largest Private Schools in Multnomah County, OR
Portland Adventist Academy
Seventh-day Adventist school · Grades 9–12
193 students
Portland, OR
B+Overall grade193 students13 students per teacher
#24 Largest Private Schools in Multnomah County, OR
Childpeace Montessori School
Montessori school · Grades Pre-K–8
186 students
Portland, OR
A+Overall grade186 students8 students per teacher
From official public records, updated October 2026.