Partner

155 University Avenue, Suite 1230
Toronto, ON, M5H 3B7

+1 416 238 2265

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John Mather is a Partner at DMG Advocates practicing commercial and public litigation. 


John is adept on his feet in any setting. He regularly appears before the Ontario Superior Court and Court of Appeal. He has acted in numerous domestic and international arbitrations, including in New York and Riyadh, Saudi Arabia. John has also appeared before various administrative and
regulatory bodies. 

From 2019-2020, John served as Associate Commission Counsel to Associate Chief Justice Frank Marrocco at the Collingwood Judicial Inquiry, an extensive public inquiry that examined two major transactions undertaken by the Town of Collingwood. In 2021, John served as Duty Counsel to Ontario’s Long-Term Care COVID-19 Commission, assisting individuals who appeared before the Commission. 


John has broad experience in matters involving: 

  • Contractual disputes 
  • Product liability 
  • Procurement (public and private) 
  • Construction disputes 
  • Professional regulation and academic appeals 
  • Internal investigations 
  • Commercial leasing, condominium and real estate matters 
  • Urgent proceedings and injunctions 
  • Municipal law and governance 
  • Administrative and regulatory proceedings 
  • Corporate governance 
  • Defamation law 
  • Constitutional law 


John’s clients have included leading automobile manufacturers, condominium boards, telecommunications providers, newspaper publishers, oil and petrochemical producers, steel manufacturers, professional service firms and restaurant franchisors, as well as government agencies, and non-profit organizations. 


Prior to joining DMG Advocates in 2018, John spent five years as an associate lawyer at a leading national firm. 


John earned his law degree from Western University, where he graduated with Distinction 


Updated March 2022