Magical Schools may not be so common as their Muggle Equivalent, but that doesn't mean there aren't several around. While this site deals with two main RolePlayed schools, the staff and students have backgrounds and links that mention other such institutions. Here is a listing:

Name	Province	Current Head
Academie du Nor	Canada	Unknown
Dalkey Institute	Dublin, Ireland	Unknown
Salem Institute	Massachusetts, USA	Selina Skies
Sonora Academy	Arizona, USA	Manfred Bulla
Youmens y Sanchez	Mexico	Unknown