Ontario Sheriff's Office

The Ontario Sheriff's Office (OSO) is the smaller of two provincial police forces responsible for law enforcement at the provincial level in Ontario, Canada's most populous province. While sheriff's deputies are legally peace officers, and thus possess the full police powers of regular law enforcement agencies including the authority to enforce the Criminal Code on behalf of the provincial government in any and all contexts, the main focus of the OSO is on areas of law enforcement and security outside the purview of the larger provincial police agency, namely the Ontario Provincial Police (OPP). While the OPP patrols provincial highways and roads, investigates crimes under provincial jurisdiction, and also contracts with regional and municipal districts to provide local policing, the Ontario Sheriff's Office is responsible for the transportation of prisoners and remanded detainees between institutions, maintaining the security of all judicial institutions and all persons within the judicial system, administering the provincial witness protection program, providing hospital guard services, protecting senior provincial government officials as well as provincial institutions, and assisting the OPP and local law enforcement agencies (county constabularies) to maintain public security and order during major events, among other responsibilities. The Sheriff of Ontario is appointed by the Solicitor General of Ontario on advice of the Premier of BC and the province's Attorney General. All other officer's of the Ontario Sheriff's Office are referred to as sheriff's deputies, or deputies for short.

Corrections Ontario operates the provincial prisons within Ontario, and jails are operated by the respective county's Department of Corrections in county areas and by the OSO in regional and municipal districts, while the OSO is responsible for the transportation of prisoners to, from and between all facilities, such as between jail and court, in all parts of the province. The OSO has the right to lay charges in consultation with the Ontario Crown Prosecution Service, but for the most part this is handled by regular police agencies, including the OPP.

Rank structure
Below is a list of all ranks of non-civilian staff (sworn officers/deputies) of the Ontario Sheriff Service, which is the same as most other provincial sheriff's services, arranged in descending order from lowest to highest.

All but the highest rank (the sheriff) can be referred to generally as deputies, as they are all law enforcement officers acting on the deputized authority of the Sheriff of Ontario. Like most other Canadian law enforcement agencies, deputies of the BCSS wear their rank insignia on their epaulettes, with the shoulder area below consisting only of the standard shoulder flash worn by BCSS personnel.