Futsal is a variant of association football that is played on a smaller pitch and mainly played indoors. Its name is a portmanteau of the Portuguese futebol de salão and the Spanish fútbol de salón (colloquially fútbol sala), which can be translated as "hall football" or "indoor football". During the sport's second world championships held in Madrid in 1985, the name fútbol Sala was used. Since then, all other names have been officially and internationally changed to futsal.

Futsal is played between two teams each with five players, one of whom is the goalkeeper. Unlimited substitutions are permitted. Unlike some other forms of indoor football, the game is played on a hard court surface delimited by lines; walls or boards are not used. Futsal is also played with a smaller ball with less bounce than a regular football. The surface, ball and rules create an emphasis on improvisation, creativity and technique as well as ball control and passing in small spaces.

As international governing bodies of futsal, FIFA and AMF are responsible for maintaining and promulgating the official rules of their respective versions of futsal. Like association football, futsal has laws that define all aspects of the game, including what may be changed to suit local competitions and leagues. There are seventeen laws in the Futsal Laws of the Game.