See also: 2002 in Canada, other events of 2003, 2004 in Canada and the list of 'years in Canada'.
Events
- January 20 - Avalanche kills eight skiers in eastern British Columbia
- February 2 - An avalanche in Glacier National Park, British Columbia, kills six boys and one girl.
- February 22nd - 2003 Canada Winter Games
- March 5 - Sui-chu Kwan, who travelled to Hong Kong in February, dies of SARS in Toronto.
- March 10 - Scarborough's Grace Hospital closes as a result of SARS, the first of many hospital to do so
- March 17 - Health Canada announces 17 suspected SARS cases in Canada
- March 26 - Ontario declares a public health emergency as a result of SARS
- April 14 - In the Quebec election Jean Charest's Liberals defeat Bernard Landry's Parti Quebecois
- April 23 - The World Health Organization issues a travel advisory against Toronto because of SARS, Canadian officials protest the decision
- April 25 - After more than two weeks with no new cases of SARS health workers begin to feel the disease is contained
- May 12 - Holly Jones, a ten year old girl, dissapears in Toronto. The next parts of her body are found floating in Lake Ontario
- May 20 - An Albertan cow is found to have been infected with BSE, the United Staes, Japan, and a number of other nations halt all imports of Canadian beef
- May 22 - SARS reemerges in a Toronto hospital
- June 9 - In the New Brunswick election Bernard Lord's Conservatives lose many seats but are reelected to a majority govenrment
- June 10 - a Toronto court rules that the ban on gay marriage is illegal, the first marriage takes place that day
- July 8 - British Columbia follows Ottawa's lead and permits same-sex marriage
- August 5 - In the Nova Scotia election John Hamm's Conservatices are reelected to a minority government
- August 9 - The United States eases its ban on Canadian beef
- August 14 - The United Church of Canada votes to approve smae-sex marriages
- August 14 - A massive blackout hits Ontario, Quebec and northeast of the United States
- September 23 - The Ward Hunt Ice Shelf, 443 square kilometres in size, in the Arctic fractures, releasing all water within a freshwater lake it contained.
- October 2 - Ontario Election. Dalton McGuinty's Liberals defeats Ernie Eves's Tories.
- October 5 - Maher Arar freed from jail in Syria
- October 21 - Newfoundalnd election, Premier Frank Grimes's Liberals are defeated by Danny Williams's Conservatives
- October 23 - Israeli airline El Al Jet is diverted twice, first to Montreal then to Hamilton, Ontario, to allow some passengers off. A threat was made against Toronto's Pearson International Airport.
- November 5 - In the Saskatchewan election Premier Lorne Clavert's NDP is reelected to a bare majority
- November 10 - Municipal elections oocur across Ontario. In the Toronto election David Miller is elected mayor.
- November 13 - The Canadian dollar value closes at a 10 year high of $ .7695 US
- November 18 - Canada offers Ontario $330 million in relief of the past summer's SARS virus impact
- November 21 - The Heritage Classic, the first outdoor game in NHL history, is played in Edmonton
- December 12 - Paul Martin, Jr. sworn in as Canada's 26th Prime Minister
Births
Television
- American Idol comes to Canada as Canadian Idol Hosted by Ben Mulroney (son of Brian Mulroney)
- Colin Mochrie leaves; Mary Walsh is expected for 6 episodes than leave; Shaun Majumder joins This Hour Has 22 Minutes
Deaths
- June 15 - Hume Cronyn, stage and film actor
- June 21 - Roger Neilson, National Hockey League coach
- July 16 - Carol Shields, author
- October 15 - Bertram N. Brockhouse, physicist