The Provincial Secretary of Quebec was a senior position in the provincial cabinet of Quebec from before Canadian Confederation until 1970.
The Provincial Secretary and Registrar was originally the second highest position in the provincial cabinet, equivalent to the position of Deputy Premier. The Provincial Secretary was the equivalent of the former Canadian Cabinet position of Secretary of State for Canada. 
Pre-Confederation Provincial Secretary.
Prior to Confederation and the creation of the office of Premier, the Provincial Secretary was the most important and powerful figure in provincial politics. The title holder was appointed by the Lieutenant Governor and many sat as members of the Legislative Council.