David C. Onley (born June 12, 1950) was the twenty-eighth Lieutenant Governor of Ontario from 2007 until 2014.
Due to an incident with a previous film crew, a ban on lights has made shooting on location at Queen's Park almost impossible for nearly a decade. Onley had to convince the Sargent-at-Arms, as well as the Speaker of the Legislative Assembly of Ontario to allow shooting in the historic building. This task was made easier by the fact that the current Speaker, Dave Levac, is also a Murdoch Mysteries fan
Onley considered playing Mowat, as well as working with the cast a crew "a distinct honour".