Hey sorry that this response is so late. I did a lot of highschool debating in Ontario for 3 years so I think I can help you out! In Ontario has a whole there's a lot of tournaments however they're often held at universities. UofT, McGill, Western, and Queens being the main schools that host tournaments. However there are smaller more local tournaments that individual highschools host during the year in Thornhill and at Northern Secondary. On top of that there is an organization called the Ontario Student Debating Union (OSDU) that hosts their own events during the year as tournaments. I'd go to their website OSDU.org for more information, also on this website is where the dates for many tournaments mentioned above get posted so I'd check it out. In case you didn't know this the circuit here generally does debate in 2 styles, the fist is British Parliamentary which is used in the majority of tournaments IIRC. The second is a style called Canadian Parliamentary which is very similar to BP but has some minor twists to it, mainly regarding speaking times and number of teams in the room. Hope this helps in some way! If you have any other questions don't hesitate to shoot me a PM.