Football, known in the United States and Canada simply as football[1], is a competitive team sport known for its physical roughness despite being a highly strategic game. The object of the game is to score points by advancing the prolate spheroid ball into the opposing team's end zone. The ball can be advanced by carrying it (a running play) or by throwing it to a teammate (a passing play). Points can be scored in a variety of ways, including carrying the ball over the goal line, throwing the ball to another player past the goal line or kicking it through the goal posts on the opposing side. The winner is the team with the most points when the time expires and the last play ends.

Outside the United States and Canada, the sport is referred to as American football (or a translation thereof) to differentiate it from other football games. In Australia and New Zealand the game is known as Gridiron, although in America the word "gridiron" refers only to the playing field.

The Gallup Poll has shown football to be America's favorite sport every year since 1972, when football first overtook baseball in popularity. The percentage of Americans who say football is their favorite sport to watch (43%) is higher now than at any other time. Football's American TV viewership ratings far surpass those of other sports.[2] The day of the National Football League championship, the Super Bowl, is one of the biggest occasions for social gatherings in the U.S. and is sometimes referred to as an unofficial national holiday.[3]

The 32-team National Football League (NFL) is the only major professional American football league.

College football is also popular throughout North America. Four college football stadiums, The University of Michigan's Michigan Stadium, Penn State's Beaver Stadium, The University of Tennessee's Neyland Stadium and Ohio State's Ohio Stadium, seat more than 100,000 fans and almost always sell out. Even high school football games can attract more than 10,000 people in some areas. The weekly autumn ritual of college and high-school football—which includes marching bands, cheerleaders, homecoming, and parties (including the ubiquitous tailgate party)—is an important part of the culture in much of smalltown America. Football is generally the major source of revenue to the athletic programs of schools, public and private, in the United States. Some private Christian High Schools even play for 'national championships' with groups like the Federated Christian Athletic Association (FCAA).

It is a long-standing tradition in the United States (though not universally observed) that high school football games are played on Friday night, college games on Saturday, and professional games on Sunday, with one NFL game played on Monday night. In recent years, however, nationally televised Thursday night college games have become a weekly fixture on ESPN.

Certain fall and winter holidays—most notably Thanksgiving and New Year's Day—have traditional football games associated with them.

Football is played recreationally by amateur and youth teams (e.g., the Pop Warner little-league programs). There are also many "semi-pro" teams in leagues where the players are paid to play but at a small enough salary that they generally must also hold a full-time job.

Organized football is played almost exclusively by men and boys, although a few amateur and semi-professional women's leagues have begun play in recent years.