Flag football is a variant of gridiron football where, instead of tackling players to the ground, the defensive team must remove a flag or flag belt from the ball carrier ("deflagging") to end a down. In flag football, contact is limited between players. The sport has a strong amateur following with several national and international competitions each year sponsored by various associations but is most popularly played in America where it was invented. The international governing body for the sport is the International Federation of American Football (IFAF). In 2022, flag football was shortlisted as a proposed discretionary event for the 2028 Summer Olympics in Los Angeles, with inclusion being accepted on October 16, 2023.

Gridiron football, also known as North American football, or in North America as simply football, is a family of football team sports primarily played in the United States and Canada. American football, which uses 11 players, is the form played in the United States and the best known form of gridiron football worldwide, while Canadian football, which uses 12 players, predominates in Canada. Other derivative varieties include arena football, flag football and amateur games such as touch and street football. Football is played at professional, collegiate, high school, semi-professional, and amateur levels.