About John

John Mastoras is a senior partner in the employment and labour law group. He focuses on complex labour and employment disputes across union and non-union workplaces in federal and provincial jurisdictions. His experience 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.

Education & credentials

Law school
Osgoode

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This listing was generated by AI from public sources in August 2026. It may contain errors, and we can’t guarantee it’s accurate or complete. Before you rely on anything here, verify it on their firm’s website. Confirm John Mastoras’s licence and standing in the Law Society of Ontario directory ↗

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