Freestyle swimming is a category of swimming competition defined by the rules of the International Swimming Federation (FINA), in which competitors are subject to only a few limited restrictions on their swimming stroke. Freestyle races are the most common of all swimming competitions, with distances ranging from 50 meters to 1,500 meters. The term "freestyle stroke" is sometimes used as a synonym for "front crawl," as front crawl is the fastest surface swimming stroke and is now the most common stroke used in freestyle competitions.

The freestyle stroke is swum in a horizontal position with the body facing down. The body rolls from one side to the other, always turning to the side of the arm that is currently pulling in the water. The head remains in a neutral position, face down, except when breathing. The freestyle swimming technique starts when your hand cuts right through the water. With your elbow above your hand, extend your arm forward as your body rolls to the side. Your shoulder should be out of the water, and your head should be turned to the side to breathe.

Freestyle swimming implies the use of legs and arms for competitive swimming, except in the case of the individual medley or medley relay events. The freestyle is most commonly chosen by swimmers, as this provides the greatest speed. During a race, the competitor circles the arms forward in alternation, kicking the feet up and down (flutter kick) . Individual freestyle events can also be swum using one of the officially regulated strokes (breaststroke, butterfly, or backstroke) .

Some general rules swimmers must follow when competing in a freestyle swim include touching the wall at every turn and keeping at least some part of their body above water at all times, except for the first 15 meters and when making turns.