Pierre Brun was born in Quebec City and obtained an undergraduate law degree at the Université Laval.   He was admitted to the Barreau du Québec in 1989.  He also obtained his masters degree in law at the Université de Montréal in 1993.  He mainly practices in the areas of civil rights and liberties, as well as labour law.

Mr. Brun co-authored "Les chartes des droits et libertés", Collection Alter Ego, Éd. Wilson et Lafleur, (from 1993 to 2001).
He is also the author of the following article: "La pollution du partage des compétences par le droit de l'environnement", published in the University of Ottawa’s Revue générale de droit, (1993).