In the United States and Canada, the term professional football includes the professional forms of American and Canadian gridiron football. In common usage, it refers to former and existing major football leagues in either country. Currently, there are multiple professional football leagues in North America: the two longest-running leagues are the National Football League (NFL) in the U.S, and the Canadian Football League (CFL) in Canada. American football leagues have existed in Europe since the late 1970s, with competitive leagues all over Europe hiring American Imports to strengthen rosters. The Austrian Football League and German Football League top division are known as the best leagues in Europe. The Japan X-League is also a strong league that has a long history since 1971. The NFL has existed continuously since being so named in 1922.

American football, also known as gridiron football, is a team sport played by two teams of eleven players on a rectangular field with goalposts at each end. The offense, the team with possession of the oval-shaped football, attempts to advance down the field by running with the ball or throwing it, while the defense, the team without possession of the ball, aims to stop the offense's advance and to take control of the ball for themselves. The offense must advance at least ten yards in four downs or plays; if they fail, they turn over the football to the defense, but if they succeed, they are given a new set of four downs to continue the drive. A game is won by the team with the higher number of points, which are scored primarily by advancing the ball into the opposing team's end zone for a touchdown or kicking the ball through the opponent's goalposts for a field goal.