See also: 2002 Canadian incumbents, Events in Canada in 2003, 2004 Canadian incumbents, Governmental leaders in 2003, Canadian incumbents by year

Federal Government

• Head of State - Queen Elizabeth II
• Governor General - Adrienne Clarkson

Cabinet

• Prime Minister - Jean Chrétien then Paul Martin

• Deputy Prime Minister - John Manley then Anne McLellan
• Minister of Finance - John Manley then Ralph Goodale
• Minister of Foreign Affairs - Bill Graham
• Minister of National Defence - John McCallum then David Pratt
• Minister of Health - Anne McLellan then Pierre Pettigrew
• Minister of Industry - Allan Rock then Lucienne Robillard
• Minister of Heritage - Sheila Copps then Hélène Scherrer
• Minister of Intergovernmental Affairs - Stéphane Dion then Pierre Pettigrew
• Minister of the Environment - David Anderson
• Minister of Justice - Martin Cauchon then Irwin Cotler
• Minister of Transport - David Collenette then Tony Valeri
• Minister of Citizenship and Immigration - Denis Coderre then Judy Sgro
• Minister of Fisheries and Oceans - Robert Thibault then Geoff Regan
• Minister of Agriculture and Agri-Food - Lyle Vanclief then Bob Speller
• Minister of Public Works and Government Services - Ralph Goodale then Stephen Owen
• Minister of Human Resources Development - Jane Stewart (position discontinued on December 11)
• Minister of Natural Resources - Herb Dhaliwal then John Efford
• Minister of Human Resources and Skills Development - Joe Volpe (position created on December 12)
• Minister of Social Development - Liza Frulla (position created on December 12)

Members of Parliament

See: 37th Canadian parliament

Opposition Leaders

• Canadian Alliance - Stephen Harper
• Bloc Québécois - Gilles Duceppe
• New Democratic Party- Alexa McDonough then Jack Layton
• Progressive Conservative Party - Joe Clark then Peter MacKay

Supreme Court Justices

• Chief Justice: Beverley McLachlin
• Frank Iacobucci
• John C. Major
• Michel Bastarache
• William Ian Corneil Binnie
• Louise Arbour
• Louis LeBel
• Marie Deschamps
• Charles D. Gonthier then Morris Fish

Other

• Speaker of the House of Commons - Peter Milliken
• Governor of the Bank of Canada - David Dodge
• Chief of the Defence Staff - General R.R. Henault

Provinces

Premiers

• Premier of Alberta - Ralph Klein
• Premier of British Columbia - Gordon Campbell
• Premier of Manitoba - Gary Doer
• Premier of New Brunswick - Bernard Lord
• Premier of Newfoundland and Labrador - Roger Grimes, then Danny Williams
• Premier of Nova Scotia - John Hamm
• Premier of Ontario - Ernie Eves, then Dalton McGuinty
• Premier of Prince Edward Island - Pat Binns
• Premier of Quebec - Bernard Landry, then Jean Charest
• Premier of Saskatchewan - Lorne Calvert
• Premier of the Northwest Territories - Stephen Kakfwi, then Joe Handley
• Premier of Nunavut - Paul Okalik
• Premier of Yukon - Dennis Fentie

Lieutenant Governors

• Lieutenant-Governor of Alberta - Lois Hole
• Lieutenant-Governor of British Columbia - Iona Campagnolo
• Lieutenant-Governor of Manitoba - Peter M. Liba
• Lieutenant-Governor of New Brunswick - Marilyn Trenholme Counsell then Herménégilde Chiasson
• Lieutenant-Governor of Newfoundland and Labrador - Edward Roberts
• Lieutenant-Governor of Nova Scotia - Myra Freeman
• Lieutenant-Governor of Ontario - James K. Bartleman
• Lieutenant-Governor of Prince Edward Island - Joseph Gérard Léonce Bernard
• Lieutenant-Governor of Quebec - Lise Thibault
• Lieutenant-Governor of Saskatchewan - Lynda M. Haverstock

Mayors

• Toronto - Mel Lastman then David Miller
• Montreal - Gérald Tremblay
• Vancouver - Larry Campbell
• Ottawa - Bob Chiarelli
• Victoria - Alan Lowe

Religious Leaders

• Roman Catholic Bishop of Quebec - Cardinal Archbishop Marc Ouellet
• Roman Catholic Bishop of Montreal - Cardinal Archbishop Jean-Claude Turcotte
• Roman Catholic Bishops of London - Bishop Ronald Peter Fabbro
• Moderator of the United Church of Canada - Marion Pardy then Peter Short