The following is a list and brief history of American football franchises that at one time played in the National Football League (NFL). The NFL was known as the American Professional Football Association (APFA) in 1920 and 1921. Note that the list represents NFL franchises that no longer exist, not franchises/teams that relocated. However, during the 1920s it is hard to tell if some teams changed nicknames from year to year or if each nickname represented a new franchise. It was also not uncommon for two or more teams to have the same nickname during the same season. No NFL franchise has folded since 1952. The Buccaneers, Colts, Cowboys, Giants, Lions, Panthers, and Texans franchises listed on this page are not the current franchises of those names. A defunct team, in this case, refers to a team which has had the rights to have a team returned to the NFL (or league collective at the time). Massillon Tigers attended the meetings in 1920, but never fielded a team in 1920.
Six defunct teams won an APFA/NFL championship: 1920 Akron Pros, 1922 and 1923 Canton Bulldogs, 1924 Cleveland Bulldogs, 1926 Frankford Yellow Jackets and 1928 Providence Steam Roller.
These are all teams that applied to join the NFL but were refused entry. Some existed only as proposals, but others had full organizations. Unless otherwise noted, each team folded after their unsuccessful bid to join the NFL.