How many swimmers are in a medley relay team?

A medley relay team has four swimmers, with each swimmer completing one leg in a different stroke.

In the standard medley-relay order, the first swimmer uses backstroke, followed by breaststroke, butterfly, and freestyle. The freestyle leg cannot use backstroke, breaststroke, or butterfly, so competitors almost always choose front crawl.

This differs from an individual medley, where one swimmer performs all four strokes. The stroke order also changes: an individual medley begins with butterfly, then backstroke, breaststroke, and freestyle. Backstroke must begin a relay because that swimmer starts in the water, while later swimmers dive from the starting blocks after their teammates touch the wall.

Medley relays are commonly raced as 4×50 or 4×100 events. Mixed medley relays also use four swimmers, normally two men and two women, although the precise event format depends on the competition rules.