St Mary's High School vs Thousand Islands Secondary School
A head-to-head comparison of two secondary schools in Ontario, Canada, 714 m apart, using official Canadian 2025 data. The better value in each row is highlighted.
St Mary's High School
Brockville · Catholic secondary · Grades 9-12
385 students
Thousand Islands Secondary School
Brockville · Public secondary · Grades 9-12
640 students
| Measure | St Mary's High School Brockville, Ontario | Thousand Islands Secondary School Brockville, Ontario |
|---|---|---|
| Success Index (Canada) | 58 Top 50% | 44 Lower 50% |
| Province rank | #295 of 766 | #452 of 766 |
| National rank | #295 of 766 | #452 of 766 |
| Sector | Catholic | Public |
| Type | Secondary | Secondary |
| Year range | Grades 9-12 | Grades 9-12 |
| Students | 385 | 640 |
| Enrolment | 385 | 640 |
| EQAO Grade 3 | – | – |
| EQAO Grade 6 | – | – |
| EQAO Grade 9 maths | 49% | 46% |
| OSSLT pass rate | 93% | 89% |
| Low-income households | 5% | 11% |
| Parents without a credential | 5% | 4% |
| First language not English | 5% | 3% |
| Special education | 30% | 38% |
| Identified as gifted | 0% | 1% |
| FSA literacy score | – | – |
| FSA numeracy score | – | – |
| FSA Grade 4 literacy score | – | – |
| FSA Grade 4 numeracy score | – | – |
| FSA Grade 7 literacy score | – | – |
| FSA Grade 7 numeracy score | – | – |
| city or town | Brockville | Brockville |
| province | Ontario | Ontario |
| Website | www.stmarychs.cdsbeo.on.ca | tiss.ucdsb.on.ca/ |
The verdict
- •St Mary's High School scores higher on the Success Index (Canada) (58.4 vs 43.5).
- •St Mary's High School does better on eqao grade 9 mathematics (49% vs 46%).
- •St Mary's High School does better on osslt first-attempt pass rate (93% vs 89%).
- •Thousand Islands Secondary School is the larger school with 640 students compared with 385.
- •St Mary's High School is a catholic school while Thousand Islands Secondary School is a public school, so fees and admission rules differ.
The Success Index (Canada) summarises published results and context from official data. It does not measure teaching quality or fit. Methodology.
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Frequently asked questions
Is St Mary's High School better than Thousand Islands Secondary School?
On the Success Index (Canada), St Mary's High School ranks higher (58.4 vs 43.5 out of 100). The index is built from published results and context data, not from teaching quality or fit, so visit both schools before deciding.
How far apart are St Mary's High School and Thousand Islands Secondary School?
About 714 m in a straight line, between Brockville and Brockville in Ontario.
Which has the better Enrolment?
St Mary's High School: 385. Thousand Islands Secondary School: 640. Students enrolled in the latest published year.
How do St Mary's High School and Thousand Islands Secondary School rank in Ontario?
St Mary's High School is 295th of 766 and Thousand Islands Secondary School is 452nd of 766 among secondary schools in Ontario on the 2025 Success Index (Canada).