CFL

Rugby football began to be played in Canada in the 1860s, and many of the first Canadian football teams played under the auspices of the Canadian Rugby Football Union (CRFU), founded in June 1880 then reorganized in February 1884. The CRFU was reorganized as the Canadian Rugby Union (CRU) in 1891, and served as an umbrella organization for several provincial and regional unions. The Grey Cup was donated by Governor General the Earl Grey in 1909 to the team winning the "Senior Amateur Football Championship of Canada". By that time, the sport as played in Canada had diverged markedly from its rugby origins with the introduction of the Burnside rules, and started to become more similar to the American game.

For much of the early part of the 20th century, the game was contested by intraprovincial leagues, or unions. In 1907, several of the stronger senior clubs in Ontario and Quebec formed the Interprovincial Rugby Football Union (IRFU or more commonly known as the "Big Four"). It took almost 30 years for an elite interprovincial western union to emerge, when in 1936 the stronger senior clubs in Manitoba, Alberta and Saskatchewan formed the Western Interprovincial Football Union (WIFU). From the 1930s to the 1950s, the Big Four and WIFU gradually evolved from amateur to professional leagues, and amateur teams were no longer competitive for the Grey Cup. Apart from the World War II years, an amateur team last won the Grey Cup in 1936.

By the end of World War II, the WIFU's play was at the same level as that of the Big Four. Within a few years after the return of peace, both interprovincial unions had turned openly professional. However, while the Big Four champion got an automatic berth to the Grey Cup final, until 1954 the WIFU's champion had to play in a semi-final against the champion of the Ontario Rugby Football Union (ORFU)–by then, the only amateur union still competing for the Grey Cup. The ORFU withdrew from Grey Cup competition after the 1953 season, and the WIFU champion was given an automatic berth in the Grey Cup final. For this reason, 1954 is reckoned as the start of the modern era of Canadian football, in which the Grey Cup has been exclusively contested by professional teams. Since 1965, Canada's top university football teams, competing in what is now U Sports, have competed for the Vanier Cup.

In 1956, the Montreal Alouettes threatened to leave the Big Four and join the rival WIFU. As a result, the Big Four and WIFU formed a new umbrella organization, the Canadian Football Council (CFC) to modernize the operations and management of the professional game. In 1958, the CFC formally left the CRU and reorganized as the Canadian Football League. As part of an agreement between the CRU and CFL, the CFL took possession of the Grey Cup, and the amateurs were officially locked out of Grey Cup play. However, the Grey Cup had been the de facto professional championship since 1954. The CRU remained the governing body for amateur play in Canada, eventually adopting the name Football Canada. Initially, the two unions remained autonomous, and there was no intersectional play between eastern (Big Four) and western (WIFU) teams except at the Grey Cup final. This situation was roughly analogous to how Major League Baseball operated for almost all of the 20th century.

The Big Four was renamed the Eastern Football Conference in 1960, while the WIFU was renamed the Western Football Conference in 1961. Also in 1961, limited intersectional play was introduced. Because the West played 16 games by this time while the East still only played 14, this arrangement oddly allowed both the four-team Eastern Conference and the five-team Western Conference to play three games per intraconference opponent and one game per interconference opponent. It was not until 1974 that the East expanded its schedule to 16 games, just like the West. In 1981, the two conferences agreed to a full merger, becoming the East and West Divisions of the CFL. With the merger came a fully balanced and interlocking schedule of 16 games per season (with all nine teams playing each other twice, once at home and once on the road). Since 1986 (with exception of 2021), the CFL's regular season schedule has been 18 games.

The separate histories of the Big Four and the WIFU accounted for the fact that two teams had basically the same name: the Big Four's Ottawa were often called the "Eastern Riders", while the WIFU's Saskatchewan were called the "Western Riders" or "Green Riders". Other team names had traditional origins. With rowing a national craze in the late 19th century, the Argonaut Rowing Club of Toronto formed a rugby team for its members' off-season participation. The football team name Toronto Argonauts still remains even though it and the rowing club have long since gone their separate ways. After World War II, the Hamilton Tigers absorbed the upstart war-era Flying Wildcats and called the team the Hamilton Tiger-Cats.

The league remained stable with nine franchises—the BC Lions, Calgary Stampeders, Edmonton Eskimos, Saskatchewan Roughriders, Winnipeg Blue Bombers, Hamilton Tiger-Cats, Toronto Argonauts, Ottawa Rough Riders and Montreal Alouettes—from its 1958 inception until 1981. After the 1981 season, the Alouettes folded and were replaced the next year by a new franchise named the Concordes.

In 1986 the Concordes were renamed the Alouettes to attract more fan support, but the team folded the next year. The loss of the Montreal franchise forced the league to move its easternmost Western team, Winnipeg, into the East Division from 1987 to 1994.

In 1993, the league admitted its first United States–based franchise, the Sacramento Gold Miners. After modest success, the league then expanded further in the U.S. in 1994 with the Las Vegas Posse, Baltimore Stallions, and Shreveport Pirates. For the 1995 campaign, the American teams were split off into their own South Division, and two more teams, the Birmingham Barracudas and Memphis Mad Dogs, were added; at the same time, the Posse folded and the Gold Miners relocated to become the San Antonio Texans. In 1995, the Stallions became the only non-Canadian team to win the Grey Cup.

Despite all American teams having the advantage of not being bound to the CFL's minimum Canadian player quotas, only the Stallions proved to be an on-field and off-field success. The establishment of the NFL's Baltimore Ravens, worsening financial problems among the league's core Canadian teams, and the inconsistent performance of the other American teams prompted the CFL to abandon its American experiment and retrench its Canadian operations. The Stallions organization was used as the basis for a revival of the Montreal Alouettes.

The CFL returned to an all-Canadian format in 1996 with nine teams; the league conducted a dispersal draft to distribute players from the disbanded American-based teams; however, the Ottawa Rough Riders, in existence since 1876, folded after the 1996 season (another dispersal draft was conducted the next year to distribute the former Rough Rider players among the remaining eight teams). Toronto and recently revived Montreal also were struggling; Montreal's woes were solved by moving to Percival Molson Memorial Stadium, a much smaller venue than the cavernous Olympic Stadium. The Winnipeg team again moved to the East Division from 1997 to 2001 to make up for the loss of Ottawa.

In 1997, the NFL provided a US$3-million interest-free loan to the financially struggling CFL. In return, the NFL was granted access to CFL players entering a defined two-month window in the option year of their contract. This was later written into the CFL's collective bargaining agreement with its players. The CFL's finances have since stabilized and they eventually repaid the loan. The CFL–NFL agreement expired in 2006. Both leagues have been attempting to reach a new agreement, but the CFL broke off negotiations in November 2007 after Canadian telecommunications firm Rogers Communications paid $78 million to host seven Bills games in Toronto over five seasons (the last Bills Toronto Series game was played during the 2013 NFL season).

In 2002, the league expanded back to nine teams with the creation of the Ottawa Renegades. After four seasons of financial losses, the Renegades were suspended indefinitely before the 2006 season; their players were absorbed by the remaining teams in a dispersal draft. Winnipeg was moved to the East Division again in 2006, a situation that continued until 2013.

In 2005, the league set an all-time attendance record with a total attendance of more than 2.3 million. In June 2006 the league announced the launch of CFL Broadband, an internet streaming service designed to provide fans with another media platform, in addition to TSN and CBC broadcasts, to watch games live.

With Mark Cohon as commissioner of the league the CFL entered a period of stability and growth. New television deals, two new collective bargaining agreements, the 100th Grey Cup celebration, and widespread stadium renovation and rebuilding highlighted this era. The 100th anniversary of the Grey Cup had the highest ever television ratings for a championship game in English Canada.

During the 2000s the CFL had the third highest per-game attendance of any North American sports league and the seventh highest per-game attendance of any sports league worldwide. A 2006 survey conducted at the University of Lethbridge confirmed that the CFL was the second most popular sports league in Canada, with the following of 19% of the total adult Canadian population compared to 30% for the NHL. The NFL had 11% following, with a total of 26% following at least one of the pro football leagues. In other words, approximately 80% of Canadian football fans follow the CFL, and about 55% follow the NFL. With the absence of Ottawa from 2006 to 2013, league attendance hovered around the 2 million mark. It stood at 2,029,875 in 2012 for a single game average of 28,193. The 2007 season was a recent high point with average game attendance of 29,167, the best since 1983.

During Mark Cohon's time in office many of the teams either undertook major renovations to their existing stadiums, or constructed brand new stadiums. The Montreal Alouettes were the first to undertake this project, adding 5,000 seats to Percival Molson Memorial Stadium in time for the 2010 CFL season. The Edmonton Eskimos and Calgary Stampeders also renovated their respective stadiums and facilities for the 2010 season. In 2011, the BC Lions played under a new, retractable roof in BC Place after spending one and a half seasons at Empire Field. In 2013, the Winnipeg Blue Bombers moved to Investors Group Field, now known as Princess Auto Stadium, an entirely new stadium at the University of Manitoba. The Hamilton Tiger-Cats began using their new stadium, Tim Hortons Field, after spending 2013 at University of Guelph's stadium and the first half of the 2014 season at McMaster University's football field following the demolition of the iconic Ivor Wynne Stadium.

In 2014 the Ottawa Redblacks kicked off their inaugural season (having been awarded a franchise in 2008), becoming the third Ottawa franchise in CFL history. The new Ottawa franchise returned the league to a nine-team structure, with five teams in the West Division and four in the East; the Winnipeg Blue Bombers moved back to the West Division. The expansion Ottawa Redblacks played at the massively renovated Frank Clair Stadium, now branded as TD Place Stadium.

In Mark Cohon's last year as commissioner he negotiated a new five-year collective bargaining agreement (from 2014 through the 2018 season) between the CFL and the Canadian Football League Players' Association (CFLPA).

The Toronto Argonauts entered a period of transition off the field, with new ownership and a new stadium. The Argonauts were sold by politician/businessman David Braley to Bell Media and MLSE chairman Larry Tanenbaum. At the start of the 2016 season the Argos moved to BMO Field after more than twenty seasons at the Rogers Centre (formerly called the SkyDome from 1989 to 2005). Construction on the New Mosaic Stadium for the Saskatchewan Roughriders was completed in October 2016 and the first game was played in the 2017 season.

In 2015, Michael Sam signed a two-year contract with Montreal Alouettes of the CFL, becoming the first openly gay player in the league's history. Sam left the team the day before the first preseason game, citing personal reasons. As reported by Fox Sports, Sam returned to Montreal to continue his professional football career. He left again on August 14, this time permanently, again citing personal reasons.

Immediately following the 2015 season Jeffrey Orridge announced a re-branding for the CFL, including a new logo, motto, uniforms for all nine teams and website. After not having a drug enforcement policy in effect for the 2015 season the league and the CFLPA agreed to a new drug policy. In 2017, the Board of Governors and Jeffrey Orridge agreed to part ways, effective June 30, 2017; Orridge cited "differing views on the future of the league" between him and the Board of Governors for the departure, with both sides stating the decision was mutual and amicable. His last day as commissioner was June 15, 2017. Jim Lawson, the CFL's Chair of the Board of Governors, took over the duties of interim Commissioner until a suitable replacement was found.

On July 5, 2017, Randy Ambrosie succeeded Orridge as CFL commissioner. Having spent nine seasons as a player with the Calgary Stampeders, Toronto Argonauts and Edmonton Eskimos from 1985 to 1993, Ambrosie is the first commissioner to have played in the league since Larry Smith left the position in 1997.

On September 12, 2018, it was announced that Buffalo, New York–based New Era Cap Company would become the official apparel supplier of the CFL beginning in 2019, replacing Adidas.

In October 2018, the CFL began focusing marketing internationally again after the unsuccessful expansion into the United States during the 1990s, with Ambrosie's plan being called CFL 2.0. Ambrosie partnered with the Professional American Football League of Mexico (LFA) for player development, as part of the league's plan to expand globally. Ambrosie also later announced a special edition of the CFL Combine to be held in 2019 in Mexico for Mexican players, which was held on January 13, 2019. Ambroise said he wished the combine in Mexico to become annual, and that a combine could be held in Europe. On January 14, 2019, the league held a draft of LFA and Mexican university players where wide receiver Diego Viamontes was the first pick, selected by the Edmonton Eskimos. The CFL announced in February 2019 that German and French football players from the German Football League and the Fédération française de football américain [fr] would participate in the CFL national combine. Throughout early 2019, Ambrosie actively travelled Europe forming partnerships between the CFL and top-level European American football leagues and associations, specifically Germany (GFL), Austria (AFL), France (FFFA), the Nordic countries (NL, VL, SS and NAFL) and Italy (IFL). By January 2020 football leagues from 13 countries had signed partnerships with the CFL, these partnerships included mutual exchanging of players and coaches with leagues like the Mexican LFA holding reserved roster spots for Canadians with up to 25 playing in the league's 2020 season. In February 2020, the CFL expanded its global alliance system, welcoming the Japanese X-League, generally regarded the third-best professional gridiron league in the world. This coincided with the CFL announcing that its global combine in 2020 with new rules, including two designated active-roster international players and three practice-squad international players with as many as 45 global players in the league.

The league took over operations of the Montreal Alouettes prior to the 2019 season after Robert C. Wetenhall, the league's last non-Canadian owner, surrendered the franchise to the league in May. The Alouettes found new ownership in January 2020 in Crawford Steel executives Sid Spiegel and Gary Stern, whose holding company S and S Sportsco would oversee the team.

On August 17, 2020, the CFL cancelled its 2020 season after coronavirus-related social distancing mandates and travel restrictions imposed in most of Canada prevented the league from selling tickets and the league was unable to secure a bailout from the federal government to cover any losses. It was the first cancelled season in the league's history, and the first year without a Grey Cup championship since the canceled 1916–1919 seasons. The league returned in 2021, playing a shortened 14-game schedule which began that August, with the season concluding with the Grey Cup game in December for the first time since 1972. On March 10, 2021, the then-on hiatus XFL entered into talks with the CFL over the possibility of a future collaboration; these discussions were called off four months later with nothing coming of them.

On August 29, 2022, Gary Stern of the Montreal Alouettes stepped away from day-to-day operations with the club and resigned from his role with the Canadian Football League's board of governors, effective immediately. On February 14, 2023, the ownership of the Alouettes was transferred back to the CFL. Mario Cecchini was appointed as the interim President while the league sought to finalize a sale to new ownership. On March 10, Quebec media mogul and former Parti Québécois leader Pierre Karl Péladeau purchased the team. On April 11, 2024, the Winnipeg Blue Bombers announced league record revenue of $50.5 million and operating profit of $5.7 million.

Ambrosie announced his resignation on October 26, 2024, to take effect following the 111th Grey Cup. Ambrosie had reportedly lost a vote of confidence among the league's owners a day prior.