The distance medley relay (DMR) is an athletic event in which four athletes compete as part of a relay. With its inclusion in the IAAF World Relays program, the IAAF announced on May 1, 2015 that the event would be an official world record event.

A relay race is a racing competition where members of a team take turns completing parts of racecourse or performing a certain action. Relay races take the form of professional races and amateur games. Relay races are common in running, orienteering, swimming, cross-country skiing, biathlon, or ice skating. In the Olympic Games, there are several types of relay races that are part of track and field. Relay race, also called Relay, is a track-and-field sport consisting of a set number of stages (legs), usually four, each leg run by different members of a team. The runner finishing one leg is usually required to pass the next runner a stick-like object known as a "baton" while both are running in a marked exchange zone. In most relays, team members cover equal distances: Olympic events for both men and women are the 400-metre and 1,600-metre relays. Some non-Olympic relays are held at distances of 800 m, 3,200 m, and 6,000 m. In the less frequently run medley relays, however, the athletes cover different distances in a prescribed order—as in a sprint medley of 200, 200, 400, 800 metres or a distance medley of 1,200, 400, 800, 1,600 metres.