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.

The 14th Canadian Parliament was in session from 8 March 1922 until 5 September 1925. The membership was set by the 1921 federal election on 6 December 1921, and it changed only somewhat due to resignations and by-elections until, due to momentary confusion among the MPs, it lost a money vote and was dissolved, causing the 1925 election.