Allan (Al) O’Brien is a senior partner at Nelligan Law, and is chair of the Partnership. Al is a graduate of the University of Ottawa and was called to the Ontario Bar in 1975.

He was the managing partner at Nelligan Law for 16 years.

Getting to know Al. Watch the video

Early in his career, he was involved in a mixed practice of civil litigation, family law, labour law and employment law. In the last ten years, his practice has focused increasingly on litigation, with particular emphasis on lawyers’ professional liability defence work, commercial litigation, and working with financial institutions. In addition, he has appeared before hundreds of administrative tribunals. He also has extensive negotiating experience, and has acted on several occasions as chief negotiator for a large public service union.

Al is active in a number of professional associations, and in 2005 he became a Fellow of the American College of Trial Lawyers. He was also inducted into the Honour Society of the University of Ottawa’s Common Law School, which is the most prestigious alumni distinction offered by the Law School. Al was honoured by The Advocates’ Society and became the recipient of The John P. Nelligan Award for Excellence in Advocacy in 2017.

Al was selected as a leading practitioner in the Canadian Legal Lexpert Directory from 2012 to 2018. He was also included in the 2006 to 2021 editions of The Best Lawyers in Canada, and was named Ottawa Corporate and Commercial Litigation “Lawyer of the Year” in the 2010 and 2014, Legal Malpractice Law “Lawyer of the Year” in 2015 and 2017, and Labour and Employment Law “Lawyer of the Year” in 2020 editions of The Best Lawyers in Canada. Al was peer rated by Martindale-Hubbell in 2016 and 2017 and ranked “Preeminent” in recognition of his high level of professional excellence.

For several years, Al was an instructor in the civil litigation section of the Bar Admission Course. On numerous occasions he has been a guest speaker on professional issues, and he has written and presented legal papers to the County of Carleton Law Association and The Law Society of Upper Canada on the subject of solicitors’ negligence. He has trained student advocates at the University of Ottawa and has participated in seminars on trial advocacy. He has also presented papers at several risk management seminars.

Al learned early on in his career that practising law is a privilege. Clients entrust him with their problems, so he strives to honour that trust by dedicating himself to the resolution of their issues. Al is passionate about meeting his clients’ expectations, and is humbled to be able to offer assistance to those in need. His reputation in the legal community is characterized by a high level of professional integrity and a client focus. He is highly organized, empathetic, and committed to the cause.

Al tries to spend most weekends up at his cottage, where he is actively involved with the local community. He maintains a healthy and physical lifestyle, and devotes most of his time outside of the office to his family and friends.


Best Lawyers Award Badge Best Lawyers Award Badge

Best Lawyers Award BadgeBest Lawyers Award Badge



Allan has been recognized in the 2006-2021 editions of Best Lawyers


  • >Call to Ontario Bar (1975)
  • >LL.B., University of Ottawa (1973)
  • >B.A., St. Patrick's College, Ottawa (1968)

Professional Activities and Organizations

  • >Fellow of the American College of Trial Lawyers
  • >Canadian Bar Association
  • >County of Carleton Law Association
  • >The Advocates' Society - Former Director
  • >Bar Admissions Course - Instructor
  • >Law Society of Upper Canada Continuing Legal Education Programs - Lecturer
  • >Lexwork International – Former member of the Americas Governing Board
  • >Lexwork International - Former representative of The International Convenors Committee