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 players 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 in matters 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 J.D. 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, the local food scene, golf, and playing music. He is a proud lifelong Calgarian with deep roots in southern Alberta and an enduring (if sometimes painful) loyalty to the Calgary Flames.
Year joined firm: 2016
Recent matter/case highlights:
- People Corporation v 2578649 Alberta Ltd. (Quinn Advisory Group) - David acts for People Corporation, a billion-dollar insurance conglomerate, seeking to enforce restrictive covenants against a departing principal. The matter is ongoing. David and JSS Barristers were successful in obtaining a partial injunction in advance of trial.
- Brown-Forman Corporation v Charton-Hobbs Inc - David acted for Brown-Forman Corporation, one of the largest liquor manufacturers in the world, in a dispute with a large Canadian agent over an unwritten distribution agreement. David and JSS Barristers were successful at trial, obtaining a judgment for nearly $1M in damages for breach of the duty of good faith contractual performance.
- JL Energy Transportation Inc v Alliance Pipeline Limited Partnership - David acts for JL Energy, an intellectual property holder, against various subsidiaries of Pembina Pipeline Corporation. The action claims over $600M in damages for infringement of patents. David and JSS Barristers were successful in overturning summary dismissal of the claim at the Court of Appeal, in a noteworthy 5-judge panel decision interpreting the constitutional interplay between the Patent at and Alberta’s Limitations Act.
- M.A. v Alberta College of Pharmacy - David acts for a pharmacist accused of professional misconduct. David was successful in obtaining two stays pending appeal, first at King’s Bench then at the Court of Appeal. The former decision led to David’s appointment as amicus curiae at the Court of Appeal on a reference case interpreting the appeal and stay provisions of the Health Professions Act (the decision on which is on reserve). The misconduct appeal is ongoing.
- TotalEnergies EP Canada v Suncor Energy and Teck Resources - David acted for TotalEnergies, one of the world’s largest energy companies, in a billion-dollar dispute involving interpretation of right of first refusal provisions on an oil sands project with the Respondents. The matter was ultimately resolved out of court by way of divestiture transaction.
Key practice areas:
- Appellate
- Arbitration
- Commercial disputes
- Dispute resolution
- Energy and construction
- Government and regulatory
- Insurance
- Labor and employment
- Plaintiff
Sector expertise:
- Energy
- Healthcare
- Insurance
- Investment management
- Oil and gas
Academic qualifications:
- Juris Doctor, University of Calgary, 2015
- BA, Philosophy, University of Calgary, 2011
- Diploma in Jazz Performance, Mount Royal University, 2006
Association/network memberships:
- The Advocate's Society, 2023
- Calgary Bar Association, 2013
- Appellate Practice, 2024
Bar Admissions: Alberta 2015
