The OPP patrols provincial highways and waterways; protects provincial government buildings and officials, with the exception of the legislative precinct; patrols unincorporated areas in northern Ontario; provides training, operational support, and funding to some Indigenous police forces; and investigates complex or multi-jurisdictional crimes across the province.

[16] The title of the commanding officer was changed to "commissioner" and given responsibility for enforcing the provisions of the Ontario Temperance Act[17] and other liquor regulations.

The OPP's first death in the line of duty occurred in 1923, when escaped convict Leo Rogers shot and killed Sergeant John Urquhart near North Bay.

Rogers, who was later killed in a shootout with OPP officers, had already mortally wounded North Bay City constable, Fred Lefebvre.

This was a body of volunteers (primarily World War I veterans) whose duty was to protect vulnerable hydroelectric plants and the Welland Ship Canal under the supervision of regular police members.

The OPP still administers First Nations policing for Big Trout Lake, Weagamow, Muskrat Dam, and Pikangikum.

Formed as the Ontario Provincial Pipes and Drums in 1968 by two constables, the band saw active service to wide acclaim in the 1970s and 80s before being disbanded in 1991 due to department financial constraints.

After this, probationary police constables are assigned to a detachment within the OPP's six regions with a coach officer for a year of field training.

Auxiliary officers wear light blue shirts, checkered hat bands, and have their own cap badges.

This close connection continues today with the OPP auxiliary playing a critical role in emergency and disaster planning and occurrences.

[64] Officers wear duty belts, which, at a minimum, carry an officer's issued use of force equipment, and also wear an external Pacific Safety Products vest with MOLLE webbing to store additional items and large placards that read "police" in gold text on their chest and back.

[65] During the 2022-23 fiscal year, the OPP engaged in a proof-of-concept program in East Region which included the use of body worn cameras (BWC), along with its accompanying mobile applications.

In March 2023, the OPP completed a provincial implementation of In-Car Camera systems with integrated ALPR into over 1,300 frontline vehicles across all regions of the province.

In 1989, in response to manufacturers no longer offering dual tone vehicles, the OPP switched to an all-white livery with blue and gold striping.

[70] Vehicles of this era had detachment markings on the rear quarter panel and used Federal Signal Arjent S2 light bars.

All marked cruisers are equipped with pushbars, also generally have black steel rims, and spotlights mounted on the driver side.

[72][73] Unmanned aerial vehicles[9] Ontario Provincial Police officers carry a variety of use of force equipment in the performance of their duties.

[citation needed] The land at the centre of the dispute was owned by a corporation planning to build a subdivision known as the Douglas Creek Estates.

Tensions led to violence and over the span of several years, the Ontario Provincial Police were criticized for perceived inaction against the native protesters by local residents.

On 4 September 1995, first nations people occupied the park to bring attention to decades-old land claims that had not been recognized, resulting in the Ipperwash Crisis.

The OPP now uses a variety of different methods in resolving conflicts at major events, most notably by the use of the Provincial Liaison Teams (PLT), formerly known as the Major Event Liaison Team (MELT)[78] In 1993 an Ontario Divisional Court case, John Doe v. Ontario (Information and Privacy Commissioner), Judge Matlow of the Ontario Divisional Court, suspected that four officers of the Toronto Police Service engaged in a fabrication of evidence and harassment of an accused party.

[80] In March 2015, the Royal Canadian Mounted Police announced they were investigating fraud allegations against three top executives of the OPPA.

[81] In 2018, Toronto Police Superintendent Ron Taverner, was nominated to replace outgoing Commissioner Vince Hawkes.

[82] The appointment of Taverner brought about controversy given the personal relationship between him and Premier Doug Ford, potential nepotism, and the OPP's role in investigating political corruption.

Ultimately, Taverner rescinded his interest in the position, resulting in the appointment York Regional Police Deputy Chief Thomas Carrique as the OPP's new commissioner.

Pepper's Lonely Hearts Club Band contains cover art with Paul McCartney wearing an OPP patch on his fictional uniform (more easily seen in the gatefold picture).

In January 2016 the origins of the patch was confirmed as a gift from an OPP corporal on 28 September 1964, at Malton Airport as the Beatles were on their way to Montreal.

In the Canadian horror film Pontypool, the OPP is called into the eponymous town to control a zombie outbreak, ultimately resulting in a massacre.