About John
John Mastoras is a senior partner in the employment and labour law group. He specializes in complex labour and employment disputes across union and non-union workplaces in federal and provincial jurisdictions. His expertise spans energy, healthcare, pharmaceutical, transportation, technology, retail, longshoring, building services and manufacturing. He received the 2026 Sefton-Williams Award from the University of Toronto for contributions to labour relations and human rights.
Practice areas
Education & credentials
- Law school
- Osgoode
Listing compiled from public sources in August 2026. Confirm John Mastoras’s licence and standing in the Law Society of Ontario directory ↗