Every private or independent school if different, and one of the strongest benefits of choosing a specialized school is that it allows your child to focus on their interests (whether sports, arts or computers) while obtaining a solid education. For example the La Citadelle International Academy of Arts and Science and St. Michael's Choir School allows students to focus on professional arts while balancing their academics, while the Athol Murray College of Notre Dame have very strong Hockey programs that prepare students for the NHL.
To find schools that specialize in arts or sports, it's best to use the Advanced Search and check off which categories you're most interested in. You can also browse the Types of Schools section of the website, each has a list of schools that fall within the specialized category.
Boarding schools in particular often have very developed sport programs. For example, Shawnigan Lake School and Brentwood College School on the west coast of Canada continue to produce olympic level rowers. Depending on the age of your child, their interest and your financial ability, if you can't find a school in the Toronto area, a boarding school may be a great opportunity for your child.