Ontario has 747 ranked secondary schools and several hundred more private schools that don’t appear in provincial rankings at all. For a parent trying to identify genuinely strong options — whether they live in Toronto, Ottawa, Oakville, or elsewhere in the province — the question isn’t “what are the best schools in Ontario” in the abstract. It’s which schools in their region are worth seriously considering, what makes each one distinct, and whether their child is ready for the academic environment those schools represent. This guide covers the province region by region.
Best high schools in Ontario: How Ontario high schools are compared
The Fraser Institute’s Report Card on Ontario’s Secondary Schools is the most comprehensive publicly available comparison tool, ranking 747 public, Catholic, and independent schools out of 10 based on provincewide test data. For a full explanation of how the rankings work and what they measure, see our Ontario high school ranking guide.
The key limitation worth restating here: the rankings measure average academic outcomes across a school’s entire student population. They do not measure whether a specific school is the right match for a specific child — particularly a high-performing child who needs an environment that will genuinely stretch them rather than one where they comfortably top every class.
GTA: the highest concentration of top schools in the province
Greater Toronto Area schools dominate the top 25 list of Ontario’s Fraser Institute rankings. York Region Catholic schools in particular — St. Robert Catholic High School in Thornhill, St. Theresa of Lisieux in Richmond Hill, and St. Augustine in Markham — hold three of four perfect scores in the 2025 report.
Within Toronto itself, St. Michael’s Choir School consistently earns a perfect Fraser Institute score and ranks as Toronto’s most academically prestigious school. Ursula Franklin Academy consistently scores above 9.5 on Fraser Institute ratings. Marc Garneau Collegiate Institute runs the TOPS program for students with a strong interest in math, science, and technology.
For a detailed breakdown of Toronto’s best public, Catholic, and independent high schools — including University of Toronto Schools, Upper Canada College, and specialty programme applications — see our dedicated best high schools in Toronto guide.
For Toronto’s top private schools specifically, including SSAT requirements and admissions timelines, see our Toronto private schools guide.
Oakville and Halton Region
Oakville is consistently one of the strongest regions in Ontario for secondary school options within the public system.
Abbey Park High School rose from a Fraser score of 8.1 to 9.3 in recent years — one of the most significant improvement trajectories in the province — despite 13.9% of its students being English Language Learners. It is currently tied as one of the province’s highest-scoring schools outside the GTA’s top cluster.
Iroquois Ridge High School also sits at 9.3 in the 2025 rankings, tied with Abbey Park. Both schools serve the growing communities of north Oakville and are consistently cited among the province’s top public schools.
Oakville also has access to several strong private school options, including schools in the broader Halton and Hamilton regions. For families considering independent schooling in the area, tuition ranges and admissions processes are broadly comparable to Mississauga — see our best private schools in Mississauga guide for context on western GTA private school norms.
Ottawa
Ottawa has a smaller but genuinely strong secondary school sector, with strong options in both the public and private systems.
Colonel By Secondary School consistently ranks as Ottawa’s top public high school. Colonel By Secondary School is top-ranked in the capital and among the province’s highest-scoring schools, with a strong IB programme and consistent academic performance. It draws students from across the city for its IB programme specifically.
Lisgar Collegiate Institute is among the oldest secondary schools in Ottawa, founded in 1843 and regularly ranked among the best in the province academically. It offers a full suite of AP coursework, plus an additional gifted programme — the first of its kind in Ontario. Located downtown and serving locally zoned students, with transfers available for students outside the catchment.
Nepean High School and Glebe Collegiate Institute are consistently cited alongside Colonel By and Lisgar as Ottawa’s strongest public academic options. Glebe offers a balance of strong academics and a vibrant extracurricular scene; Nepean is known for strong science and technology programming.
Canterbury High School is Ottawa’s dedicated public arts high school, where students audition for specialised streams in visual art, music, drama, dance, and more alongside a complete Ontario curriculum.
On the private side, Ashbury College (co-ed, Grade 4–12, boarding and day) offers both the Ontario Secondary School Diploma and an IB programme. While technically Anglican, religion does not have a major influence on the school’s culture. Elmwood School is Ottawa’s established girls’ independent school, offering day and boarding from JK through Grade 12.
For families in Ottawa applying to private schools, the SSAT is accepted at Ashbury and several other Ottawa independents. See our SSAT guide for Canadian parents for preparation guidance.
Best high schools in Ontario: Waterloo Region
Waterloo Region is distinctive in Ontario for reasons beyond school rankings. It is home to the University of Waterloo — the institution behind Canada’s most widely sat mathematics competition series (Gauss, Pascal, Cayley, Fermat, Euclid) — and schools in the region tend to have stronger mathematics cultures and higher contest participation rates than provincial averages.
For families with mathematically strong students, this matters as much as a school’s Fraser Institute score. A school in the Waterloo region with active CEMC contest participation and a strong mathematics department may offer a more enriching environment for a high-performing math student than a higher-ranked school elsewhere with no competition mathematics culture.
For more on the CEMC contest pathway and how to prepare, see our University of Waterloo math contest guide.
Hamilton and mid-size Ontario cities
Hamilton is home to one of the province’s most discussed school improvement stories. Georges-P.-Vanier in Hamilton rose from 2 out of 10 in 2018 to 7.1 in 2024, placing it among the province’s fastest climbers. This is a meaningful trajectory for a mid-size city school, demonstrating that geographic location is not a fixed constraint on academic performance.
Hillfield Strathallan College in Hamilton is one of the province’s established independent schools, offering a co-educational environment from JK through Grade 12 with a strong emphasis on university preparation and a range of enrichment opportunities.
Other Ontario cities with strong secondary options include Kingston (where Queen’s University creates a strong academic culture in the surrounding school community), London, and Windsor — all of which have a mix of well-regarded public and Catholic schools alongside smaller independent options.
Best high schools in Ontario: What to look for beyond the ranking
For families with high-performing, academically ambitious students, a few factors matter more than the overall Fraser score:
Competition mathematics culture. Does the school actively support CEMC contest participation? Are there teachers who can coach students beyond the standard curriculum? This matters far more for a mathematically gifted student than whether the school’s average Grade 9 EQAO score is 7.2 or 8.5.
IB and AP availability. Both programmes provide meaningful enrichment and university admissions advantages. IB is more internationally recognised; AP offers subject-specific university credit courses. Check which programme is available before narrowing your school list.
Specialty programme applications. Many of Ontario’s best public schools have specialty programmes — gifted, IB, arts, science and technology — that require separate applications and sometimes entrance assessments. These programmes are often where a high-performing student will actually be placed rather than in the school’s general stream.
Private school admissions timing. For independent schools across Ontario, applications typically close by December 1 for September entry. The SSAT, where required, should be written by November at the latest. Families who begin researching in January are already behind.
For a complete guide to independent school options across the province, see our private schools in Ontario guide.
How Think Academy Canada supports Ontario families
Think Academy Canada works with motivated, high-performing students across Canada from Grade 1 through Grade 12, fully online. Our programmes are built around competition mathematics, curriculum enrichment, and SSAT preparation — the three areas most relevant to families making ambitious high school choices across Ontario.
Our starting point is always a free diagnostic. Every student who completes our assessment receives a personalised feedback report showing exactly where their academic skills currently sit, along with free practice resources matched to the results. For families currently choosing between school options, the assessment gives you an individual picture that no ranking or comparison tool can provide.
FAQ
What are the best high schools in Ontario?
The province’s highest-ranked public schools in 2025 include St. Robert Catholic (Thornhill), St. Theresa of Lisieux (Richmond Hill), St. Augustine Catholic (Markham), St. Michael’s Choir School (Toronto), Abbey Park (Oakville), and Colonel By (Ottawa). Strong independent schools include Upper Canada College, Branksome Hall, Ashbury College, and Hillfield Strathallan College.
Are GTA high schools better than schools in the rest of Ontario?
GTA schools dominate the top of provincial rankings, but strong schools exist across the province. Colonel By in Ottawa, Abbey Park in Oakville, and Lisgar Collegiate in Ottawa all consistently rank among the province’s best. Regional strength varies by city and school type.
What is the best public high school outside Toronto in Ontario?
Colonel By Secondary School in Ottawa and Abbey Park High School in Oakville are consistently cited as the strongest public high schools outside Toronto, both with high Fraser Institute scores and strong specialist programmes.
Do Ontario’s best high schools require an entrance exam?
Public school placement is generally based on home address, except for specialty programmes (IB, gifted, arts) which require separate applications and sometimes assessments. Independent schools typically require the SSAT or their own entrance assessment for Grade 7 and Grade 9 entry.
What is the best high school in Ottawa?
Colonel By Secondary School is consistently Ottawa’s top-ranked public high school, known for its IB programme. Lisgar Collegiate is also highly regarded, offering AP courses and a gifted programme. Ashbury College and Elmwood School are the most established private options.
What is the best high school in Oakville?
Abbey Park High School and Iroquois Ridge High School both scored 9.3 in the 2025 Fraser Institute rankings — among the highest in the province outside the GTA’s top cluster.
Are Catholic high schools better than public high schools in Ontario?
Catholic schools frequently appear at the top of Ontario rankings, with three of four perfect scores in 2025 coming from York Region Catholic schools. However, many public schools rank equally highly, and the right choice depends on a family’s values and a student’s specific programme needs.
How does competition mathematics fit into Ontario high school choice?
For mathematically strong students, a school’s participation in CEMC contests (Gauss, Pascal, Cayley, Fermat, Euclid) and its mathematics enrichment culture matter as much as its overall ranking. Schools in Waterloo Region tend to have particularly strong competition mathematics cultures given proximity to the University of Waterloo.
How can Think Academy Canada help with Ontario high school preparation?
Think Academy Canada offers a free diagnostic assessment for students in Grades 1 to 12. The assessment identifies where a student’s academic skills currently sit, giving families a clear, individual starting point for high school preparation across any region of Ontario.
About Think Academy Canada Think Academy Canada is a K-12 mathematics tutoring programme, part of TAL Education Group. We work with motivated, high-performing students across Canada from Grade 1 through Grade 12, with a focus on curriculum enrichment, SSAT preparation, and competition mathematics including CEMC and AMC. All lessons are delivered online. Follow us on Instagram at @thinkacademyca.
