There is an increasingly pressing issue in Canadian cities related to under-enrolment and the consolidation of schools, which has recently been recognised in the City of Toronto. As a result, a number of school buildings must be closed and sold. This paper addresses the trend of adaptive reuse as an alternative to demolition and new development of surplus school sites. Through an analysis of three case studies: Stinson School in Hamilton, Saint Michael’s High School in Niagara Falls and Queen Elizabeth Park High School in Oakville, the benefits and constraints of adaptive reuse of surplus school sites are detailed. Recommendations are made for future adaptive reuse of school sites in order to capture the potential benefits and mitigate the constraints. These recommendations can enhance the adaptive reuse process in municipalities, specifically in Toronto, to redevelop existing built-up areas and reinforce policies of sustainability, smart growth, intensification and place-making.