St Mary's High School
🇨🇦 Official data · 2025Brockville, Ontario K6V4N5 · CDSB of Eastern Ontario
#295 of 766 secondary schools in Ontario
#295 of 766 nationally
About St Mary's High School
St Mary's High School is a catholic secondary located in Brockville, in the CDSB of Eastern Ontario school board or district of Ontario, Canada. It caters for Grades 9-12. In 2025 it enrolled 385 students. Publicly funded Catholic (separate) school boards in Ontario; free to attend.
Its Success Index (Canada) is 58.4 out of 100, placing it in the top 50% of secondary schools in Canada and 295th of 766 ranked secondary schools in Ontario. Its strongest component is community advantage (fewer low-income households) (84th percentile), and its weakest is eqao grade 9 mathematics (36th percentile).
Other published figures: enrolment 385; first language not english 5%; special education 30%; identified as gifted 0%.
There are 15 schools in Brockville; St Mary's High School ranks 6th of 14 scored schools there.
Success Index (Canada) breakdown
Each component is a percentile against secondary schools across Canada.
- EQAO Grade 3 (reading, writing, maths) (20%)–
- EQAO Grade 6 (reading, writing, maths) (25%)–
- EQAO Grade 9 mathematics (25%)49%
- OSSLT first-attempt pass rate (20%)93%
- FSA literacy score (25%)–
- FSA numeracy score (25%)–
- Community advantage (fewer low-income households) (10%)5%
- Parent education (fewer parents without a credential) (10%)5%
The Success Index (Canada) summarises published data about a school community. It is not a measure of teaching quality. Read the methodology.
Published measures
All figures published for St Mary's High School by the official sources.
- Enrolment
- 385
- Students enrolled in the latest published year.
- EQAO Grade 9 maths
- 49%
- % at or above the provincial standard in Grade 9 mathematics.
- OSSLT pass rate
- 93%
- % passing the Grade 10 literacy test on the first attempt.
- Low-income households
- 5%
- % of students living in low-income households.
- Parents without a credential
- 5%
- % of students whose parents have no degree, diploma or certificate.
- First language not English
- 5%
- % of students whose first language is not English.
- Special education
- 30%
- % of students receiving special education services.
- Identified as gifted
- 0%
- % of students identified as gifted.
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Schools near St Mary's High School
Closest schools by straight-line distance, with their Success Index (Canada).
St Mary's Separate School
Brockville · Catholic elementary · Grades 7-8
175 students · 2 m away
Westminster Public School
Brockville · Public elementary · Grades JK-6
370 students · 133 m away
Thousand Islands Secondary School
Brockville · Public secondary · Grades 9-12
640 students · 714 m away
Thousand Islands Intermediate School
Brockville · Public elementary · Grades 7-8
220 students · 724 m away
BCI Intermediate School
Brockville · Public elementary · Grades 7-8
150 students · 1.2 km away
Brockville Collegiate Institute
Brockville · Public secondary · Grades 9-12
425 students · 1.2 km away
Vanier Public School
Brockville · Public elementary · Grades JK-6
250 students · 1.2 km away
St Francis Xavier Separate School
Brockville · Catholic elementary · Grades JK-6
80 students · 1.3 km away
St John Bosco Catholic School
Brockville · Catholic elementary · Grades JK-6
260 students · 1.5 km away
J L Jordan Separate School
Brockville · Catholic elementary · Grades JK-6
150 students · 1.7 km away
Similar schools
Catholic secondary schools in Ontario with a comparable Enrolment.
ÉSC Saint-Jean-de-Brébeuf
Welland · Catholic secondary · Grades 9-12
390 students
École secondaire catholique régionale de Hawkesbury
Hawkesbury · Catholic secondary · Grades 9-12
380 students
Loyola Community Learning Centre
Kingston · Catholic alternative · Grades 9-12
375 students
O'Gorman High School
Timmins · Catholic secondary · Grades 9-12
370 students
ÉSC Sainte-Trinité
Oakville · Catholic secondary · Grades 9-12
365 students
St Thomas Aquinas High School
Kenora · Catholic secondary · Grades 9-12
365 students
Frequently asked questions
Is St Mary's High School a good school?
St Mary's High School has a Success Index (Canada) of 58.4 out of 100 (Top 50% of secondary schools in Canada) and ranks #295 of 766 in Ontario. The index summarises published data about the school community and, where available, attainment; it does not measure teaching quality, so visit the school and ask about support at your child's level.
Where does St Mary's High School rank in Ontario?
St Mary's High School ranks #295 of 766 secondary schools in Ontario and #295 of 766 nationally on the Success Index (Canada) (2025 data).
How many students attend St Mary's High School?
St Mary's High School had 385 students in 2025.
Is St Mary's High School a elementary school or a secondary school?
St Mary's High School is classified as a secondary covering Grades 9-12. It is a catholic school.
What other schools are near St Mary's High School?
There are 10 schools within 15 km of St Mary's High School; they are listed on this page with their Success Index (Canada) and distance, and can be compared side by side.