He is also the grand-nephew of Lawrence Arthur Dumoulin Cannon, a long-time Liberal politician and Supreme Court judge.

He is the great-grandson[citation needed] of Sir Charles Fitzpatrick, defender of Louis Riel and former Senior Minister in Laurier's cabinet.

The extended Cannon family has had strong regional and national political influence in Canada for over a century and is considered to be influential as one of Canada's hereditary ruling class families, members having served in positions as lawyers, judges, Supreme Court judges, senators, ministers of defence, solicitors general, and members of parliament.

He graduated in political science from the Université de Montréal in 1971; and then worked for Liberal Premier Robert Bourassa as correspondence secretary, leaving in 1976 for higher academic studies.

He worked then in private sector as a financial analyst for Société de développement industriel until 1981; and then as head of Les Radiateurs Roy ltée from September 1981, to December 1985.

Cannon worked in private industry as vice-president of Unitel; now AT&T Canada Corp. during the AT&T takeover of the Canadian firm; and in other concerns between 1994 and 2001 primarily in the field of information technologies.

Cannon was elected as councillor for Gatineau City Council in 2001, representing Hull's Val-Tétreau District, under mayor Yves Ducharme.

During his mandate, the STO developed a BRT (Bus Rapid Transit) project called "Rapibus", that has since been completed.

Although Cannon and his family have historically supported the federal Liberals, he switched to the Conservative Party of Canada in the early 2000s.

[5] Many pundits had predicted that Cannon would also be named Deputy Prime Minister of Canada, but Harper chose not to retain that office.

[10][11] On August 30, 2010, the Federal Court refused a motion by Canadian government lawyers seeking to prevent the suit against Cannon from proceeding.