This article includes the world record progression for the 4×100 metres medley relay, and it shows the chronological history of world record times in that competitive swimming event. The 4×100 metres medley relay is a medley race in which each of four swimmers on a team swims a 100-metre leg of the relay, each swimming a different stroke, in the following sequence:
- Backstroke ;
- Breaststroke;
- Butterfly;
- Freestyle.
The heats for the men's 50 metre freestyle race at the 2009 World Championships took place on 31 July and 1 August 2009 (final) at the Foro Italico in Rome, Italy.
The men's 100 metre butterfly event at the 2009 World Aquatics Championships took place between 31 July – 1 August at the Foro Italico. Both the heats and semifinals were held on 31 July with the heats being held in the morning session and the semifinals being held in the evening session. The final was held on 1 August.
The heats for the Men's 200 metre Individual Medley race at the 2009 World Championships took place in the morning and evening of 29 July and the final took place in the evening session of 30 July at the Foro Italico in Rome, Italy. The order of swimming in the medley was butterfly, backstroke, breaststroke, freestyle.
The men's 400 metre individual medley event at the 2009 World Aquatics Championships took place on August 2 at the Foro Italico. The heats were held during the morning session and the final were held during the evening session. This swimming event used medley swimming. Because the swimming pool is 50 metres long, this race consisted of eight lengths of the pool. The first two lengths were swum using the butterfly stroke, the second pair with the backstroke, the third pair of lengths in breaststroke, and the final two were freestyle. Unlike other events using freestyle, swimmers could not use butterfly, backstroke, or breaststroke for the freestyle leg; most swimmers use the front crawl in freestyle events.
The women's 200 metre individual medley competition of the swimming events at the 2011 World Aquatics Championships took place July 24 and 25. The heats and semifinals took place July 24 and the final was held July 25.
The men's 200 metre individual medley competition of the swimming events at the 2011 World Aquatics Championships took place July 27 and 28. The heats and semifinals took place July 27 and the final was held July 28.
The men's 100 metre backstroke event in swimming at the 2013 World Aquatics Championships took place on 29–30 July at the Palau Sant Jordi in Barcelona, Spain.
The women's 200 metre individual medley event in swimming at the 2013 World Aquatics Championships took place on 28–29 July at the Palau Sant Jordi in Barcelona, Spain.
Hali Flickinger is a retired American professional swimmer who specializes in freestyle, butterfly, and individual medley events. She represents the Cali Condors of the International Swimming League.
The women's 200 metre individual medley event at the 2016 Summer Olympics took place on 8–9 August at the Olympic Aquatics Stadium.
Regan Smith is an American competitive swimmer. As of 2022, Smith trains under Bob Bowman with the Arizona State University professional training group. She is the world junior record holder in the women's long course 100-meter backstroke and 200-meter backstroke and a former world record holder in the long course 100-meter backstroke and the 200-meter backstroke. She competed at the 2020 Summer Olympics in three events representing the United States, winning a bronze medal in the 100-meter backstroke, a silver medal in the 200-meter butterfly, and a silver medal in the 4×100-meter medley relay. At the World Aquatics Championships, she won individual gold medals in the 200-meter backstroke in 2019 and the 100-meter backstroke in 2022 and a relay gold medal swimming the backstroke leg of the 4x100 medley relay in 2023.
Stephanie Rice (AUS)
Katie Hoff (USA)
