For the most part, each office is under the jurisdiction of the provincial Attorney General (or the Minister of Justice in Quebec), who is responsible for the conduct of criminal prosecutions at the provincial level.
Large cities like Toronto have several Crown Attorney Offices.
Each office reports to the provincial Attorney General (or Minister of Justice).
In British Columbia, Nova Scotia and Quebec, the "Director of Public Prosecutions" (or Direction générale des poursuites publiques) is responsible for criminal cases.
For federal criminal cases, the Public Prosecution Service of Canada is the responsible entity.