Throughout its history, the National Football League (NFL) and other rival American football leagues have used several different formats to determine their league champions, including a period of inter-league matchups to determine a true national champion.

The National Football League (NFL) is a professional American football league that consists of 32 teams, divided equally between the American Football Conference (AFC) and the National Football Conference (NFC). The NFL is one of the major professional sports leagues in the United States and Canada and the highest professional level of American football in the world. Each NFL season begins annually with a three-week preseason in August, followed by the 18-week regular season which runs from early September to early January, with each team playing 17 games and having one bye week. Following the conclusion of the regular season, seven teams from each conference advance to the playoffs, a single-elimination tournament that culminates in the Super Bowl, which is contested in February and is played between the winners of the AFC and NFC championship games.