Mondor holds a Bachelor of Civil Law degree from the Université du Québec à Montréal and was admitted to the Bar of Quebec in 1984.Newly appointed judges of the Court of Quebec, Tribunaux judiciaires du Québec, accessed 19 November 2012. He was a criminal lawyer and administrator prior to his appointment to the bench. He served as treasurer of the Montreal Defence Lawyers' Association from 1990 to 1999 and was a spokesperson for this organization during a December 1996 defense lawyers' strike, which was called to protest the Quebec government's proposed changes to divorce law and cuts to legal aide."Daudelin's arrest discredits Quebec justice system" [editorial], Montreal Gazette, 6 March 1996, B3; "Lawyers' strike stills courthouse," Montreal Gazette, 13 December 1996, A4. He later served as the association's president in 2002–03.Me Denis Mondor, Ad. E., Bar of Quebec, accessed 19 November 2012.
