This fonds consists of microfiche copies of manuscript diaries written by King covering his university education, entry into the civil service, achievements as Minister of Labour and his election in 1919 as Leader of the Liberal Party, the Liberal victory of 1921 and the King-Byng controversy. The manuscripts are contained in consecutively numbered fiches. Typewritten transcripts of the diaries are included in a second series of microfiches. Also included are various private typewritten diaries relating to international relations and industrial relations. An index accompanies the microfiches. The records in this fonds range from 1893 to 1931.

This addition to the fonds consists of microfiches of manuscript and typescript diaries and microfiches of typed transcriptions of diaries of William Lyon Mackenzie King dated from 1932 to 1949. These are additions to microfiches purchased in 1975.