12th Parliament of Canada
Majority parliament
15 November 1911 – 6 October 1917
Parliament leaders
Prime Minister	Robert Borden 10 October 1911 – 10 July 1920
Cabinet	9th Canadian Ministry
Leader of the Opposition	Wilfrid Laurier 10 Oct. 1911 – 17 Feb. 1919
Party caucuses
Government	Conservative Party & Liberal-Conservative
Opposition	Liberal Party
Crossbench	Labour
House of Commons
Seating arrangements of the House of Commons
Speaker of the Commons	Thomas Simpson Sproule 15 November 1911 – 2 December 1915
	Albert Sévigny 12 January 1916 – 7 January 1917
	Edgar Nelson Rhodes 18 January 1917 – 5 March 1922
Senate
Speaker of the Senate	Auguste Landry 23 October 1911 – 2 June 1916
	Joseph Bolduc 3 June 1916 – 6 February 1922
Government Senate Leader	James Alexander Lougheed 10 October 1911 – 28 December 1921
Opposition Senate Leader	Richard John Cartwright 6 October 1911 – 24 September 1912
	George William Ross 24 September 1912 – 7 March 1914
	Hewitt Bostock 19 March 1914 – 1 January 1919
Sovereign
Monarch	George V 6 May 1910 – 20 January 1936
Governor General	Prince Arthur 13 Oct. 1911 – 11 Nov. 1916
	The Duke of Devonshire 11 Nov. 1916 – 11 Aug. 1921
Sessions
1st session 15 November 1911 – 1 April 1912
2nd session 21 November 1912 – 6 June 1913
3rd session 15 January 1914 – 12 June 1914
4th session 18 August 1914 – 22 August 1914
5th session 4 February 1915 – 15 April 1915
6th session 12 January 1916 – 18 May 1916
7th session 18 January 1917 – 20 September 1917
← 11th → 13th

The 12th Canadian Parliament was in session from 15 November 1911 until 6 October 1917. The membership was set by the 1911 federal election on 21 September 1911, and it changed only somewhat due to resignations and by-elections until it was dissolved prior to the 1917 election. At 5 years, 10 months and 22 days, it was the longest parliament in Canadian history. The parliament was extended beyond the normal limit of five years by the British North America Act, 1916 as a result of World War I.

It was controlled by a Conservative/Liberal-Conservative majority under Prime Minister Sir Robert Borden and the 9th Canadian Ministry. The Official Opposition was the Liberal Party, led by Wilfrid Laurier. The last year of the wartime parliament was dominated by the Conscription Crisis of 1917. At the end of the parliament, a new ministry, the Union Government, was formed by Borden as a wartime coalition government including Liberals. Laurier refused to join and those Liberals who supported Borden took the name Liberal Unionists. The Union Government went on to win the 1917 federal election.

The Speaker was first Thomas Simpson Sproule, and later Albert Sévigny. See also List of Canadian electoral districts 1907-1914 for a list of the ridings in this parliament.

There were seven sessions of the 12th Parliament:

List of members

Following is a full list of members of the twelfth Parliament listed first by province, then by electoral district. Party leaders are italicized. Parliamentary secretaries is indicated by "‡". Cabinet ministers are in boldface. The Prime Minister is both. The Speaker is indicated by "(†)".

Electoral districts denoted by an asterisk (*) indicates that district was represented by two members.

Alberta

British Columbia

Manitoba

New Brunswick

Nova Scotia

Ontario

Prince Edward Island

Quebec

Saskatchewan

Yukon

By-elections