 
Law enforcement in Canada is the responsibility of police services, special constabularies, and civil law enforcement agencies, which are operated by every level of government, some private and Crown corporations, and First Nations. In contrast to the United States or Mexico, and with the exception of the Unité permanente anticorruption (English: Permanent Anti-corruption Unit) in Quebec and the Organized Crime Agency of British Columbia, there are no organizations dedicated exclusively to the investigation of criminal activity in Canada. Criminal investigations are instead conducted by police services, which maintain specialized criminal investigation units in addition to their mandate for emergency response and general community safety.
Canada's provinces are responsible for the development and maintenance of police forces and special constabularies, and every province except Newfoundland and Labrador delegates this responsibility to municipalities, which can establish their own police forces or contract with a neighbouring community or the province for police services. Civil law enforcement, however, is the responsibility of the level or agency of government that developed those laws — the by-laws of a transit authority, for example, are enforced by that transit authority, while federal environmental regulations are enforced by the federal government. The federal government maintains its own police force, the Royal Canadian Mounted Police (RCMP, popularly known in English-speaking areas as the "Mounties"), which provides federal criminal law enforcement and contract police services to provinces and municipalities that do not maintain their own police forces.
Since the 1990s, a framework has existed for First Nations to establish their own police services, funded entirely by the federal and provincial governments and regulated by provinces. These police services generally receive less funding compared to other Canadian police forces — for example, in 2016, the Nishnawbe-Aski Police Service in Ontario received only 36% of the funding that the Ontario Provincial Police estimated it would cost to police the same area.
Police services.
Police services in Canada are responsible for the maintenance of the King's peace through emergency response to and intervention against violence; investigations into criminal offences and the enforcement of criminal law; and the enforcement of some civil law, such as traffic violations. Constitutionally, the delivery of police services is the responsibility of provinces and territories, but every province except for Newfoundland and Labrador, which maintains the Royal Newfoundland Constabulary to police some of its urban communities, delegates this responsibility to municipalities. The federal government also maintains its own police service, the Royal Canadian Mounted Police, which provinces and territories can contract to provide provincial and municipal policing. Every Canadian territory and province, with the exceptions of Ontario and Quebec, relies on the RCMP to provide at least some provincial or municipal police services.
The exact duties of Canadian police forces vary significantly: each province regulates the basic responsibilities of police services in their jurisdiction. In Ontario, for example, police services are obliged to provide at least five core police services — crime prevention, law enforcement, maintenance of the public peace, emergency response, and assistance to victims of crime — to fulfill the province's requirement for "adequate and effective policing," while in neighbouring Quebec, the responsibilities of a police force are dependent on the population it serves. Other jurisdictions, such as Manitoba and British Columbia, do not define adequate and effective policing, although individual regulations in both of those provinces set out basic responsibilities of police forces. Individual police services may also take on additional duties, such as municipal by-law enforcement, or have a narrower mandate (but not fewer powers) in communities that maintain independent traffic enforcement or mental health crisis response agencies.
Federal.
The federal government maintains two police forces: the Royal Canadian Mounted Police (RCMP) and the Canadian Forces Military Police (CFMP).
The RCMP's first responsibility is the enforcement of federal laws, although contract policing for provinces, territories, municipalities, and First Nations is at the "heart of what the RCMP does." In addition to its contracts with three territories, eight provinces, 150 municipalities, and more than 600 Indigenous communities, the RCMP is responsible for border integrity; overseeing Canadian peacekeeping missions involving police; managing the Canadian Firearms Program, which licenses and registers firearms and their owners; and the Canadian Police College, which provides police training to Canadian and international police forces. The force has faced criticism for its uniquely broad mandate, and a partially-redacted 2019 memo to then-Minister of Public Safety Bill Blair "confirmed" for the Minister that "federal policing responsibilities have been and are being eroded to meet contract demands." Between 2012 and 2020, the RCMP gradually closed its money laundering and financial crimes units in British Columbia and Ontario, and in 2019, there were no RCMP officers in B.C. dedicated to investigating money laundering. In 2021, an all-party federal parliamentary committee recommended terminating the RCMP's contract policing program, and Public Safety Minister Marco Mendicino was mandated to conduct a review of RCMP contract policing when he took office in 2022.
The CFMP provides police, security, and operational support services to the Canadian Armed Forces (CAF) and the Department of National Defence (DND). As a military police force, the CFMP does not have a frontline community policing role, but CFMP members are considered peace officers under the Criminal Code. CFMP officers have authority over any person subject to the Code of Service Discipline (CSD), regardless of their position or rank, and can charge members of the broader public when a crime is committed on or in relation to DND property or assets, or at the request of the Minister of Public Safety, the Commissioner of the Correctional Service of Canada, or the Commissioner of the Royal Canadian Mounted Police. The ability of CFMP members to enforce provincial legislation varies, however, and in several provinces, CFMP officers can enforce neither traffic legislation nor mental health legislation — even on military bases. The CFMP maintains an investigations branch, the Canadian Forces National Investigation Service, which has the ability to investigate any crime concerning DND property or employees, except for sexual assault and intimate partner violence.
Railway police.
Under the "Railway Safety Act", any federally-regulated railway in Canada can request that a superior court judge appoint railway employees as police officers. These officers are hired, trained, and employed by the railway for the purposes of preventing crimes against the company and the protection of goods, materials, and public rail transit being moved through the railway network, and have nationwide jurisdiction within 500 metres of a railway line or as it relates to railway operations. As of 2023, the Canadian National Railway, the Canadian Pacific Kansas City railway, and Via Rail — a Crown Corporation — each maintain their own police service. 
TransLink, the transit authority for the Metro Vancouver Regional District in British Columbia, maintains a police force authorized by the province as opposed to the federal "Railway Safety Act". Some smaller railways and transit authorities, such as GO Transit, also maintain provincially-regulated special constabularies to protect passengers and property. These agencies are authorized by provincial governments and are not related to federally-authorized "Railway Safety Act" police forces.
Railway police have attracted scrutiny and criticism for their privately-funded nature and role in investigating train derailments. In 2020, a former Canadian Pacific Police Service officer alleged that he was ordered to stop investigating a fatal railway derailment to protect the railway's interests.
Provincial police.
There are six provincial police services in Canada, maintained by four provinces, although only three are involved in frontline policing. The Ontario Provincial Police and Sûreté du Québec provide provincial police services to Ontario and Quebec, respectively, the Royal Newfoundland Constabulary provides community and provincial police services to select urban communities in Newfoundland and Labrador, and the Organized Crime Agency of British Columbia, the Unité permanente anticorruption, and the Bureau des enquêtes indépendantes provide specialized criminal law enforcement services in British Columbia and Quebec.
The Ontario Provincial Police and Sûreté du Québec are responsible for both provincial police services, such as the policing of provincial highways, investigation of major crimes, and protection of provincial leaders, and the delivery of local police services to municipalities that do not maintain their own police forces, usually under contract. In Ontario, the OPP provides police services to municipalities without independent police forces regardless of whether or not there is a contract in place for them to do so, but contracts enable municipalities to direct police priorities, have a role in selecting detachment commanders, and review police service performance, including complaints, on a regular basis. In Quebec, contract police services are available to any municipality — outside of those in urban agglomerations — with fewer than 50,000 residents. In 2021, a provincial committee recommended that the population threshold for contract police services be raised to 130,000 residents and that police forces serving populations under this threshold be folded into the Sûreté du Québec. 
The Royal Newfoundland Constabulary is a provincial police force, but does not provide provincial police services across the entire province. Instead, the responsibility for provincial police services is split between the RCMP, which provides local and provincial police services to Newfoundland and Labrador's largely rural interior, and the Constabulary, which provides local and provincial police services to the northeast Avalon Peninsula (metropolitan St. John's); the Bay of Islands and the Humber Valley (metropolitan Corner Brook); and western Labrador (Churchill Falls, Labrador City, and Wabush).
The Organized Crime Agency of British Columbia (OCABC) is legally defined as a designated policing unit, and is the "core agency" of the Combined Forces Special Enforcement Unit – British Columbia (CFSEU-BC). Although the OCABC still technically exists as of 2022, its officers are limited to conducting operations and investigations within the CFSEU-BC, where it has been it largely superseded by RCMP and municipal police officers seconded to the unit. Despite its status as the core agency of the combined unit, the CFSEU-BC is governed by RCMP policies and procedures rather than the policies and procedures of the OCABC. Although the Metro Vancouver Transit Police and Stlʼatlʼimx Tribal Police Service fall into the same designated policing unit category as the OCABC, they have neither the province-wide mandate nor the direct provincial funding the OCABC does.
The Unité permanente anticorruption was created in 2011 and tasked with investigations into corrupt government procurement practices, but relied on secondments from other police services until 2018, when it became its own police force. The Quebec "Police Act" also defines the Bureau des enquêtes indépendantes as a provincial police force, but its role is strictly limited to police oversight and its members are appointed as peace officers only for the purposes of investigating police shootings, allegations of sexual assault made against police officers, and other investigations against police officers and special constables as directed by the Minister of Public Security.
Municipal police.
Municipal police forces make up the bulk of Canadian police services, and are generally responsible for all criminal matters within their jurisdiction. There are municipal police services in nine provinces, with 12 in British Columbia, seven in Alberta, 12 in Saskatchewan, 10 in Manitoba, 44 in Ontario, 31 in Quebec, nine in New Brunswick, 10 in Nova Scotia, and three in Prince Edward Island. Almost every major city in Canada maintains a municipal police service, and the majority of municipal police forces serve urban areas exclusively. Many rural communities also operate police services, however, and several have only a handful of police officers. The police services in the Town of Luseland, Saskatchewan, and the Rural Municipality of Cornwallis, Manitoba both have one officer each. As the delivery of police services is a provincial responsibility, each province has its own set of standards that police services must meet. In several provinces, such as Ontario, police services must be able to provide 24/7 coverage, investigate all criminal matters, and provide for specialized units such as police dogs, while other provinces allow small police forces to rely on outside resources to routinely supplement their patrols and investigations. Some provinces, such as Manitoba, do not define a minimum standard of "adequate and effective" policing, while others, such as Quebec, authorize several tiers of police forces based on the size of the municipality, with the lowest tiers providing only basic patrol and law enforcement functions and the highest tiers responsible for all law enforcement, investigations, and policing in their jurisdiction.
Beginning in the 1970s, and continuing into the 1990s, several municipal police forces were amalgamated (alongside, in many cases, the municipalities they served) into new, regional organizations in the interest of