David Marshall

David J. Marshall is a partner at JSS Barristers in Calgary, where he focuses on complex business disputes, specializing in shareholder litigation, corporate governance, professional regulation, and oil and gas litigation. Known for his calm, strategic approach in high‑stakes environments, David has acted as lead counsel at all levels of court in Alberta and has appeared in other jurisdictions across Western Canada.

His experience spans urgent injunctions, professional negligence, and multi‑million‑dollar commercial arbitrations, often involving highly technical subject matter and expert‑driven disputes. He has acted for major participants in the energy, insurance, and liquor industries and has played key roles in disputes involving billion‑dollar transactions and novel legal issues. David has also been appointed as amicus curiae by the Alberta Court of Appeal on a public interest matter of statutory interpretation, underscoring his credibility with the bench.

Before his legal career, David studied jazz performance and philosophy, backgrounds that inform his clarity of thought and adaptability in litigation. He earned his Juris Doctor from the University of Calgary, where he received numerous academic awards and volunteered with Student Legal Assistance.

Outside of practice, David enjoys time with his family, exploring the local food scene, golfing, and playing music. He is a proud lifelong Calgarian with deep roots in southern Alberta.

• M.A. v. Alberta College of Pharmacy. David acted for a pharmacist accused of professional misconduct and was successful in overturning the finding of unprofessional conduct at the Court of Appeal. Prior to that, he obtained two stays pending appeal at King’s Bench and the Court of Appeal. The decision led to David’s appointment as amicus curiae on a reference interpreting appeal and stay provisions of the Health Professions Act, providing important clarification for regulated colleges.

• JL Energy Transportation Inc. v. Alliance Pipeline Limited Partnership. David acts for an intellectual property holder claiming over $600 million in damages for patent infringement against subsidiaries of Pembina Pipeline Corporation. David and JSS Barristers successfully overturned the summary dismissal of the claim at the Court of Appeal in a notable five‑judge panel decision interpreting the constitutional interplay between the Patent Act and Alberta’s Limitations Act.

• People Corporation v. 2578649 Alberta Ltd. (Quinn Advisory Group). David acted for a billion‑dollar insurance conglomerate seeking enforcement of restrictive covenants against a departing principal. David and JSS Barristers successfully obtained a partial injunction in advance of trial. The matter is ongoing.

• Brown‑Forman Corporation v. Charton‑Hobbs Inc. David acted for one of the world’s largest liquor manufacturers in a dispute over an unwritten distribution agreement. David and JSS Barristers were successful at trial, obtaining nearly $1 million in damages for breach of the duty of good faith contractual performance.

• TotalEnergies EP Canada v. Suncor Energy and Teck Resources. David acted for TotalEnergies in a billion‑dollar dispute involving interpretation of right of first refusal provisions on an oil sands project. The matter was ultimately resolved through a divestiture transaction.