The Canadian Football League or CFL ( [LCF] in French) is a professional sports league located in Canada. The CFL is the highest level of competition in Canadian football, a form of gridiron football closely related to American football. Its eight current teams, which are located in eight separate cities, are divided into two divisions of four teams each — the East Division and the West Division. The league's 19-week regular season runs from late June to early November; each team plays 18 games with one bye week. Following the regular season, the three teams with the best records in their division (except if the fourth place team in one division has a better record than the third place team in the other division, when the team with the better record makes the playoffs and "crosses over" to the other division's playoff) compete in the league's three-week divisional playoffs, which culminate in the late-November Grey Cup championship, the country's largest annual sports and television event.

The CFL was officially founded on January 19, 1958, making it the second oldest gridiron football league in North America still in operation, although all its teams long predate the modern formation of the league. It is the highest level of play in Canadian football, the most popular football league in Canada, and the second-most popular major sports league in Canada, after the National Hockey League. Although ice hockey is Canada's most popular sport, the CFL has increased the popularity of Canadian football in Quebec and Western Canada. Canadian football is also played at amateur levels (i.e. youth, high school, CJFL, QJFL, CIS and senior leagues such as the Alberta Football League).

The 2010s will be a significant decade for the CFL in terms of growth, as teams have renovated, expanded stadiums, or plan to build entirely new stadiums. The Montreal Alouettes accomplished this first, 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. Then the Winnipeg Blue Bombers will play in an entirely new stadium at the University of Manitoba, scheduled to open in time for the 2013 season. The Hamilton Tiger-Cats, Saskatchewan Roughriders and the new Ottawa franchise are also looking at new or extensively-renovated stadiums in the following years. There are also hopes of expanding the league to Atlantic Canada (ideally basing a team in either the more populated Halifax, or the more centralized Moncton), as 2010 and 2011 had regular season games hosted in Moncton.

According to sports historian Douglas Brei, the Canadian Football League holds the distinction of being the only professional sports league in North America, major or minor league, in which each existing franchise has won at least one league title while in their current location.