
The Twelfth Canadian Ministry was the first cabinet chaired by Prime Minister William Lyon Mackenzie King. It governed Canada from 29 December 1921 to 28 June 1926, including the 14th Canadian Parliament and most of the 15th. The government was formed by the Liberal Party of Canada. Mackenzie King was also Prime Minister in the Fourteenth and Sixteenth Canadian Ministries.
Ministers
- Prime Minister 29 December 1921 – 29 June 1926: William Lyon Mackenzie King
- Minister of Agriculture 29 December 1921 – 29 June 1926: William Richard Motherwell
- Minister of Customs and Excise 29 December 1921 – 5 September 1925: Jacques Bureau 5 September 1925 – 29 June 1926: Georges Henri Boivin
- Secretary of State for External Affairs 29 December 1921 – 29 June 1926: William Lyon Mackenzie King
- Minister of Finance 29 December 1921 – 5 September 1925: William Stevens Fielding 5 September 1925 – 29 June 1926: James Robb
- Receiver General of Canada 29 December 1921 – 29 June 1926: The Minister of Finance (Ex officio) 29 December 1921 – 5 September 1925: William Stevens Fielding 5 September 1925 – 29 June 1926: James Robb
- Minister presiding over the Department of Health 29 December 1921 – 15 April 1926: Henri Sévérin Béland 15 April 1926 – 29 June 1926: John Campbell Elliott
- Minister of Immigration and Colonization 29 December 1921 – 3 January 1922: Vacant (William J. Black was acting) 3 January 1922 – 20 February 1922: Hewitt Bostock (acting) 20 February 1922 – 17 August 1923: Charles Stewart 17 August 1923 – 7 September 1925: James Robb 7 September 1925 – 13 November 1925: George Newcombe Gordon 13 November 1925 – 29 June 1926: Charles Stewart (acting)
- Superintendent-General of Indian Affairs 29 December 1921 – 29 June 1926: The Minister of the Interior (Ex officio) 29 December 1921 – 29 June 1926: Charles Stewart
- Minister of the Interior 29 December 1921 – 29 June 1926: Charles Stewart
- Minister of Justice 29 December 1921 – 4 January 1924: Sir Jean Lomer Gouin 4 January 1924 – 30 January 1924: Ernest Lapointe (acting) 30 January 1924 – 29 June 1926: Ernest Lapointe
- Attorney General of Canada 29 December 1921 – 28 June 1926: The Minister of Justice (Ex officio) 29 December 1921 – 4 January 1924: Lomer Gouin 4 January 1924 – 30 January 1924: Ernest Lapointe (acting) 30 January 1924 – 29 June 1926: Ernest Lapointe
- Minister of Labour 29 December 1921 – 13 November 1925: James Murdock 13 November 1925 – 8 March 1926: James Horace King (acting) 8 March 1926 – 29 June 1926: John Campbell Elliott
- Leader of the Government in the Senate 29 December 1921 – 29 June 1926: Raoul Dandurand
- Minister of Marine and Fisheries 29 December 1921 – 30 January 1924: Ernest Lapointe 30 January 1924 – 29 June 1926: Pierre Joseph Arthur Cardin
- Minister of Militia and Defence 29 December 1921 – 1 January 1923: George Perry Graham
- Minister of Mines 29 December 1921 – 29 June 1926: Charles Stewart
- Minister of National Defence 1 January 1923 – 28 April 1923: George Perry Graham 28 April 1923 – 17 August 1923: Edward Mortimer Macdonald (acting) 17 August 1923 – 29 June 1926: Edward Mortimer Macdonald
- Minister of the Naval Service 29 December 1921 – 1 January 1923: George Perry Graham
- Postmaster General 29 December 1921 – 29 June 1926: Charles Murphy
- President of the Privy Council 29 December 1921 – 29 June 1926: William Lyon Mackenzie King
- Minister of Public Works 29 December 1921 – 3 February 1922: Hewitt Bostock 3 February 1922 – 29 June 1926: James Horace King
- Minister of Railways and Canals 29 December 1921 – 19 January 1923: William Costello Kennedy 19 January 1923 – 28 April 1923: Vacant (Graham Airdrie Bell was acting) 28 April 1923 – 1 March 1926: George Perry Graham 1 March 1926 – 29 June 1926: Charles Avery Dunning
- Secretary of State of Canada 29 December 1921 – 26 September 1925: Arthur Bliss Copp 26 September 1925 – 13 November 1925: Walter Edward Foster 13 November 1925 – 24 March 1926: Charles Murphy (acting) 24 March 1926 – 29 June 1926: Ernest Lapointe
- Registrar General of Canada 29 December 1921 – 28 June 1926: The Secretary of State of Canada (Ex officio) 29 December 1921 – 26 September 1925: Arthur Bliss Copp 26 September 1925 – 13 November 1925: Walter Edward Foster 13 November 1925 – 24 March 1926: Charles Murphy (acting) 24 March 1926 – 29 June 1926: Ernest Lapointe
- Minister of Soldiers' Civil Re-establishment 29 December 1921 – 15 April 1926: Henri Sévérin Béland 15 April 1926 – 29 June 1926: John Campbell Elliott
- Solicitor General of Canada 29 December 1921 – 11 April 1923: Daniel Duncan McKenzie 11 April 1923 – 14 November 1923: Vacant 14 November 1923 – 23 May 1925: Edward James McMurray 23 May 1925 – 5 September 1925: Vacant
- Minister of Trade and Commerce 29 December 1921 – 17 August 1923: James Robb 17 August 1923 – 13 November 1925: Thomas Andrew Low 13 November 1925 – 29 June 1926: James Robb (acting)
- Minister without Portfolio 29 December 1921 – 29 June 1926: Raoul Dandurand 29 December 1921 – 17 August 1923: Thomas Andrew Low 30 December 1921 – 30 October 1925: John Ewen Sinclair 12 April 1923 – 17 August 1923: Edward Mortimer Macdonald 20 September 1924 – 30 October 1925: Harold McGiverin 9 September 1925 – 7 January 1926: Herbert Meredith Marler 16 September 1925 – 13 November 1925: Vincent Massey 20 February 1926 – 7 April 1926: George Perry Graham
Offices not of the Cabinet
Parliamentary Secretary of Soldiers' Civil Re-establishment
- 29 December 1921 – 29 June 1926: Vacant
- 5 September 1925 – 29 June 1926: Lucien Cannon
Not of the Ministry
Parliamentary Under Secretary of State for External Affairs
- 29 December 1921 – 27 October 1922: Lucien Turcotte Pacaud