The Canadian Union of Public Employees (French: Syndicat canadien de la fonction publique; CUPE–SCFP) is a Canadian trade union serving the public sector – although it has in recent years organized workplaces in the non-profit and para-public sector as well. CUPE–SCFP is the largest union in Canada, representing some 700,000 workers in health care, education, municipalities, libraries, universities, social services, public utilities, transportation, emergency services and airlines. Over 60 per cent of CUPE–SCFP's members are women, and almost a third are part-time workers. CUPE–SCFP is affiliated with the Canadian Labour Congress and is its greatest financial contributor.

CUPE–SCFP was formed in 1963 in a fashion resembling industrial unionism by merging the National Union of Public Employees (NUPE) and the National Union of Public Service Employees (NUPSE). The first national president was Stan Little, who had previously been the president of NUPSE. Having led public sector unionism through a period where almost no workers had the right to strike, Little has been credited with bringing public sector unions "from collective begging to collective bargaining." By the time of Little's retirement, CUPE–SCFP had already grown to 210,000 members and had eclipsed United Steelworkers as the largest affiliate to the Canadian Labour Congress.

Little was followed in 1975 by Grace Hartman, a feminist activist who was the first woman to lead a major labour union in North America. Hartman led CUPE–SCFP to involve itself in broader struggles for social justice and equality, and emphasized the role of social unionism, as opposed to the more conservative business unionism practised by many North American unions. She was arrested for leading Ontario hospital workers in defying a back-to-work order from the Ontario Supreme Court in 1981 and sentenced to 45 days in jail. She retired in 1983.

Hartman's successor as president was Jeff Rose, a Toronto city worker. Rose's time as the defining face of CUPE–SCFP was marked by membership growth from 294,000 to 407,000 members (largely through organizing), a strengthening of CUPE–SCFP's infrastructure and rank-and-file skills, and his outspoken opposition to Brian Mulroney-era wage restraint, free trade, the GST, privatization, deregulation, and cuts to public services. Under Rose's leadership, CUPE–SCFP was particularly effective in improving pay and working conditions for women. He stepped down in 1991 after eight years, becoming deputy minister of intergovernmental affairs for the Ontario NDP government.

In 1991, Judy Darcy followed Rose and became the defining face of CUPE–SCFP. One of Canada's most visible and colourful labour leaders, Darcy was a vigorous opponent of privatization, two-tier health care, and free trade agreements. Darcy was firmly committed to the union's involvement in broader social issues, and under her tenure CUPE–SCFP strongly attacked the invasion of Iraq, condemned Canada's involvement in ballistic missile defence, and spoke out loudly in favour of same-sex marriage. Darcy stepped down in 2003 after 12 years as president, and was replaced by Paul Moist.

On November 4, 2022, more than 55,000 CUPE–SCFP education workers began an indefinite strike against the Ontario government. Ontario Premier Doug Ford attempted to stop the strike by using the notwithstanding clause, which was criticized by Canadian Prime Minister Justin Trudeau as "wrong and inappropriate."

On October 7, 2023, the day Hamas attacked Israel, in which Hamas terrorists killed 1,200 people and took scores captive, Fred Hahn, general vice president of CUPE, tweeted: "Palestine is rising, long live the resistance." Eighty Jewish members of CUPE took Hahn and CUPE Ontario to the Ontario Human Rights Tribunal, saying they felt “isolated, unwelcome, scared, silenced, discriminated against, threatened and harassed” by the way their union had responded since the October 7 attack.

In August 2024, National President Mark Hancock said that Hahn had been asked to respond to a request from the union’s national executive board that he resign due to a social media video post by Hahn that Hancock called "antisemitic." Hahn, for his part, said that he was refusing to step down. Richard Marceau, vice president of the Centre for Israel and Jewish Affairs (CIJA), opined that CUPE should remove Hahn. Carrie Silverberg, one of the people who signed on to the human-rights complaint against CUPE, called Hahn's video “blatantly anti-Semitic”. Ontario’s labour minister, Dave Piccini, confronted Hahn and asked him to stop being anti-Semitic, and Premier Doug Ford said that Hahn's post was "bigoted". Hancock said that if Hahn does not resign on his own, "that’ll be new ground again for CUPE and me as a national president. I will review options available to me."

CUPE–SCFP has an extremely decentralized structure, in which each local elects its own executive, sets its own dues structure, conducts its own bargaining and strike votes, and sends delegates to division and national conventions to form overarching policy. Advocates of this system claim that it places the power in the grassroots where it belongs; critics believe that it makes it difficult for it to organize concerted action and leaves the union highly balkanized with policies and strategies varying widely from local to local and sector to sector. This decentralized structure is often described as "CUPE–SCFP's greatest strength and its greatest weakness." This political decentralization is mirrored by an organizational decentralization. Although CUPE–SCFP has a national headquarters in Ottawa, it is relatively small—the vast majority of its staff are scattered across over 70 offices across the country.

CUPE–SCFP locals are affiliated directly to the National body, and affiliation in Provincial CUPE–SCFP bodies is optional. CUPE–SCFP National provides locals with support and assistance through National Representatives, who are employees of CUPE–SCFP National. National Representatives are assigned to specific locals to assist the democratically elected officers of CUPE–SCFP locals in various aspects of the operation and functioning of the local union. They primarily assist in more complex issues, such as conducting Grievance Arbitrations, bargaining, disability/accommodation issues, human rights, preparation of legal documents, local elections and education. National Representatives also have authority to place a CUPE–SCFP local under administration, pursuant to the CUPE–SCFP Constitution, which effectively means that the Representative runs the local for a brief period of time in an extraordinary circumstance and suspends the locally elected officers, usually only in very serious cases of fraud or gross incompetence or misconduct. In addition to servicing National Representatives, CUPE–SCFP National employs Research Representatives and Legal & Legislative Representatives, who provide research and legal support to locals through their servicing representatives.

Nationally, there are two full-time political positions: the National President (currently Mark Hancock) and the National Secretary-Treasurer (currently Candace Rennick).

CUPE–SCFP divisions are the political voice of members in their respective provinces, and an integral part of CUPE–SCFP. Chartered through the national union, each division advocates and campaigns at the provincial level for legislative, policy and political change in the interests of CUPE–SCFP members and the communities they serve. Each provincial division is led by a democratically elected president, secretary-treasurer and executive board, who are directed by members at annual conventions (biennial in Quebec). Provincial organizations do not provide any servicing or support to the locals on specific operational items, focusing primarily on provincial lobbying, policy development and union education.

CUPE–SCFP's employees have organized into two main bargaining units. The Canadian Staff Union (CSU) is the larger of the groups. It represents National Representatives and specialist staff in Area and Region Offices across the 10 Regions of CUPE–SCFP. In 2008, CSU absorbed the Administrative and Technical Staff Union which represented about 60 administrative and technical staff at the Ottawa National Office. The Canadian Office and Professional Employees union (COPE) Local 491 represents support staff workers in the national, regional and area offices of CUPE–SCFP. Additionally, a handful of CUPE–SCFP Locals have dedicated CUPE–SCFP staff working in their own offices.

• 1963–1975: Stan Little
• 1975–1983: Grace Hartman
• 1983–1991: Jeff Rose
• 1991–2003: Judy Darcy
• 2003–2015: Paul Moist
• 2015–present: Mark Hancock

• 1963–1967: Robert P. Rintoul
• 1967–1975: Grace Hartman
• 1975–1985: Kealey Cummings
• 1985–1989: Jean-Claude Laniel
• 1989–1991: Judy Darcy
• 1991–2001: Geraldine McGuire
• 2001–2011: Claude Généreux
• 2011–2021: Charles Fleury
• 2021–present: Candace Rennick

There is a Canadian Union of Public Employees fond at Library and Archives Canada. The archival reference number is R5440, former archival reference number MG28-I234. The fond covers the date range 1919 to 2009. It contains 105.46 meters of textual records, along with a number of other media records.

• Official website
• Canadian Union of Public Employees – Web Archive created by the University of Toronto Libraries