CISAA – Conference of Independent Schools Athletic Association
Ontario Independent schools as defined by the Conference
COSSA – Central Ontario Secondary Schools Association
The counties of Haliburton, Northumberland, Hastings, Peterborough, Victoria, and PEI
CWOSSA – Central Western Ontario Secondary Schools Association
The counties of Bruce, Grey, Dufferin, Waterloo, Brant, Norfolk and Wellington
EOSSAA – Eastern Ontario Secondary Schools Athletic Association
The counties of Renfrew, Frontenac, Lanark, Leeds and Grenville, Stormont Dundas and Glengarry, Prescott and Russell, and Lennox and Addington
GBSSA – Georgian Bay Secondary School Association
The county of Simcoe, the districts of Muskoka and Parry Sound
GHAC – Golden Horseshoe Athletic Conference
The County of Halton and schools within the Hamilton-Wentworth Catholic District School Board
LOSSA – Lake Ontario Secondary School Association
The region of Durham plus Courtice Secondary School, Bowmanville High School, and St. Stephen’s Secondary School in Bowmanville
NCSSAA – National Capital Secondary School Athletic Association
The city of Ottawa
NEOAA/AANEO – North Eastern Ontario Athletic Association/Association athlétique du nord-est de l’Ontario
The districts of Cochrane and Timiskaming
NOSSA – Northern Ontario Secondary School Athletics
The districts of Manitoulin, Sudbury, Algoma, Nipissing and the regional municipality of Sudbury
NWOSSAA – Northwestern Ontario Secondary Schools Athletics Association
The districts of Kenora, Rainy River, Thunder Bay and Patricia
ROPSSAA – Region of Peel Secondary School Athletic Association
The regional municipality of Peel and schools within the Peel District School Board and Dufferin-Peel Catholic District School Board
SOSSA – Southern Ontario Secondary Schools Association
The regional municipality of Niagara South, the counties of Haldimand, Lincoln and the schools within the Hamilton-Wentworth District School Board
SWOSSAA – South Western Ontario Secondary Schools Athletic Association
The counties of Essex, Kent and Lambton
TDCAA – Toronto District Catholic Athletic Association
Catholic high schools within the City of Toronto, and independent high schools within the boundaries of the City of Toronto
TDSSAA – Toronto District Secondary School Athletic Association
Public high schools within the City of Toronto
WOSSAA – Western Ontario Secondary Schools Athletic Association
The counties of Huron, Perth, Middlesex, Elgin and Oxford
YRAA – York Region Athletic Association
The region of York