The National Football League (NFL) is the largest professional American football league. It is an unincorporated association controlled by its members. It was formed by eleven teams in 1920 as the American Professional Football Association (the league changed the name to American Professional Football League in 1921 and then settled on its current name in 1922). The league currently consists of thirty-two teams from American cities and regions, divided evenly into two conferences — the American Football Conference (AFC) and National Football Conference (NFC) — of four four-team divisions.

The regular season is a seventeen-week schedule during which each team has one bye week and plays sixteen games. This schedule includes six games against a team's divisional rivals, as well as several inter-division and inter-conference games. The season currently starts on the Thursday night in the first full week of September (the Thursday after Labor Day) and runs weekly to late December or early January.

At the end of each regular season, six teams from each conference play in the NFL playoffs, a twelve-team single-elimination tournament that culminates with the NFL championship, the Super Bowl. This game is held at a pre-selected site which is usually a city that hosts an NFL team. The following week, selected all-star players from both the AFC and NFC meet in the Pro Bowl, currently held in Honolulu, Hawaii.

The NFL has the highest per-game attendance of any domestic professional sports league in the world, drawing over 67,000 spectators per game for each of its two most recently completed seasons in 2006 and 2007. However, the NFL's overall attendance is only approximately 20% of that of Major League Baseball, due to MLB's much longer schedule, currently 162 games per team with 81 home games each, plus playoffs.