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 Schools 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 Schools Association
The region of Durham plus Courtice Secondary School, Bowmanville High School, and St. Stephen's Secondary School in Bowmanville
NCSSAA - National Capital Secondary Schools 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 Schools Association
The districts of Manitoulin, Sudbury, Algoma, Nipissing and the regional municipality of Sudbury
NWOSSAA - North Western Ontario Secondary Schools Athletic Association
The districts of Kenora, Rainy River, Thunder Bay and Patricia
ROPSSAA - Region of Peel Secondary Schools 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 College Athletic Association
Catholic high schools within the City of Toronto, and independent high schools within the boundaries of the City of Toronto not operated under the regular Ministry of Education Boards in the area, but not those which are members of the CISAA. Toronto District Secondary School Athletic Association TDSSAA Public high schools within the City of Toronto
TDSSAA - Toronto District Secondary Schools 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 Oxfor
YRAA - York Region Athletic Association
The region of York
