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About Denis

Denis Mahoney is a labour and employment partner in our St. John’s office and a member of the firm’s Board of Directors. Noted for his solid understanding of the current labour and employment issues employers face, Denis has developed a reputation as a trusted advisor and proactive problem solver.

Denis has extensive experience advising employers in the oil and gas, mining, transportation, construction and service sectors on a wide range of labour and employment matters. He provides advice on collective bargaining, drug and alcohol testing, cannabis in the workplace, and occupational health and safety matters, and serves as employer-counsel before administrative proceedings including arbitration, labour relations boards, and human rights.

A key element of Denis’ approach is his ability to address client concerns in a timely manner while maintaining a sense of humour. He has strong relationships with the employers he represents, helping them find effective solutions in often difficult situations.

A sought-after presenter and panelist, Denis frequently receives requests to speak at national, regional and local seminars and conferences, and provides training and education on a variety of labour and employment topics.

Denis is a director on the Board of the Newfoundland and Labrador Oil and Gas Industries Association (“NOIA”), TaskforceNL Inc. and the St. John’s Boys and Girls Club. He recently completed his appointment as Vice-Chair of Memorial University’s Board of Regents and is a Member of the Advisory Committee for the Centre for Law in the Contemporary Workplace at Queen’s University. Denis previously served as Chair of the St. John’s Board of Trade and as a member of the firm’s management team.

When he’s not in problem-solving mode, Denis is either spending time with Jacqueline, their 3 grown children and 3 grandchildren, or swimming, skidooing or woodcutting.


  • Best Lawyers 20212019; 2017 Labour and Employment Law “Lawyer of the Year” in St. John’s
  • Recognized as a leading practitioner in the 2019 Canadian Legal Lexpert® Directory for his practice in Employment Law; Indigenous Law; Labour Law; OH&S Law; and Workers’ Compensation Law
  • 2015 Provincial Litigation Star under Employment Law in Benchmark Canada
  • 2014 Lexpert Zenith Award
  • Recognized annually in Best Lawyers in Canada for Labour & Employment Law practice (since 2006)


  • LL.B., Queen's University (1993)
  • B.Comm. (Hons.), Memorial University of Newfoundland (1987)

Bar Admissions

  • Newfoundland & Labrador (1994)


  • English