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.
Unlike most track relays, each member of the team runs a different distance. A distance medley relay is made up of a 1200-meter leg (three laps on a standard 400 meter track), a 400-meter leg (one lap), an 800-meter leg (two laps), and a 1600-meter leg (four laps) in that order. The total distance run is 4000 meters, or nearly 2.5 miles. Aside from the 400 meter segment, which is a sprint, all legs are a middle distance run. Prior to going metric, the distance medley relay consisted of a 440-yard leg, an 880-yard leg, a 1320-yard leg and a one-mile leg. The total distance for the old distance medley relay was 4400 yards and the total distance for the current metric distance medley relay is 4374.45 yards - slightly over 25 yards shorter than the old race.
The United States currently holds world record in the men's DMR with a time of 9:15.50, set on May 3, 2015. This was set during the 2015 IAAF World Relays at Thomas Robinson Stadium, located in Nassau, Bahamas. The team consisted of Kyle Merber 2:53.56 (1200m), Brycen Spratling 45.95 (400m), Brandon Johnson 1:44.75 (800m), and Ben Blankenship 3:51.24 (1600m). They shaved off 0.06s from Kenya's previous world record time set in 2006.
The Kenyan team of 2006 ran the DMR in 9:15.56, currently the second fastest time ever run. At the time of the IAAF announcement of world record status, this mark became the ratified world record. Elkanah Angwenyi in 2:50.8 (1,200 meters), Thomas Musembi in 45.8 (400), Alfred Yego in 1:46.2 (800) and Alex Kipchirchir in 3:52.8 (1,600). This mark was set on April 29, 2006, at the Penn Relays in Philadelphia, Pennsylvania.
The Oregon Track and Field team of Cole Hocker in 2:49.89 (1,200 meters), Luis Peralta in 47.29 (400), Charlie Hunter in 1:47.65 (800), and Cooper Teare in 3:54.61 (1,600) currently hold the indoor world best in a time of 9:19.42. The mark was set on January 29, 2021 at the Razorback Invitational in Fayetteville, Arkansas. 
At the same 2015 IAAF World Relays, the women's world record was set by the American team of Treniere Moser 3:18.38 (1200m), Sanya Richards-Ross (50.12) (400m), Ajee' Wilson 2:00.08 (800m), and Shannon Rowbury 4:27.92 (1600m) running 10:36.50. They beat the outdoor record of 10:48.38 set by a team from Villanova University of Kathy Franey (1200m), Michelle Bennett (400m), Celeste Halliday (800m), and Vicki Huber (1600m) at the Penn Relays in April 1988 in Philadelphia, Pennsylvania 27 years earlier.
The United States women's team of Sarah Brown, Mahagony Jones, Megan Krumpoch, and Brenda Martinez set the first indoor world record for the event with a time of 10:42.57 at New Balance Indoor Grand Prix in 2015. At the time of the IAAF announcement, this time, superior to the best time outdoors, became the ratified world record even though it was set on an indoor banked track.
This record was broken by the United States team with a time of 10:40.31, set at the New Balance Indoor Grand Prix on January 28, 2017. The team consisted of Olympic medalist Emma Coburn 3:18.40 (1,200m), Sydney McLaughlin 52.32 (400m), Brenda Martinez, member of the old record setting team, in 2:01.92 (800 m) and in addition Olympic medalist and former world 1,500m champion Jenny Simpson 4:27.66 (1600 m).
|1||9:15.50||USA||Kyle Merber, Brycen Spratling, Brandon Johnson, Ben Blankenship||3 May 2015||Nassau|
|2||9:15.56||Kenya||Elkanah Angwenyi, Thomas Musembi, Alfred Yego, Alex Kipchirchir||29 April 2006||Philadelphia|
|3||9:15.63||USA||Chris Lukezic, James Carter, Khadevis Robinson, Bernard Lagat||29 April 2006||Philadelphia|
|4||9:16.34||Ethiopia||Aisinet Abiyot, Bereket Desta, Mohammed Aman, Aman Wote||27 April 2013||Philadelphia|
|5||9:17.01||Kenya||Anthony Chemut, Kennedy KipKosgei Chepsiror, Timothy Kitum, Caleb Ndiku||27 April 2013||Philadelphia|
|6||9:17.20||Kenya||Abednego Chesebe Miti, Alphas Leken Kishoyian, Ferguson Cheruiyot Rotich, Timothy Cheruiyot||3 May 2015||Nassau|
|7||9:17.48||Morocco||Mohammed Moustaoui, Marouan Maadadi, Mohammed Laalou, Amine Laalou||30 April 2011||Philadelphia|
|8||9:17.56||Australia||Ryan Gregson, Sean Wroe, Lachlan Renshaw, Jeff Riseley||30 April 2011||Philadelphia|
|9||9:18.09||USA||Bernard Lagat, Michael Tinsley, Duane Solomon, Russell Brown||30 April 2011||Philadelphia|
|10||9:18.21||USA||Andrew Wheating, Quentin Summers, Duane Solomon, David Torrence||27 April 2013||Philadelphia|
|1||10:36.50||USA||Treniere Moser, Sanya Richards-Ross, Ajee' Wilson, Shannon Rowbury||2 May 2015||Nassau|
|2||10:40.31 i||USA||Emma Coburn, Sydney McLaughlin, Brenda Martinez, Jenny Simpson||28 January 2017||Boston|
|3||10:42.57 i||New Balance||Sarah Brown, Mahogany Jones, Megan Krumpoch, Brenda Martinez||7 February 2015||Boston|
|4||10:42.79 i||New York All-Stars||Stephanie Charnigo, Katie Hoaldridge, Latavia Thomas, Nicole Tully||7 February 2015||Boston|
|5||10:43.35||Kenya||Selah Jepleting Busienei, Joy Nakhumicha Sakari, Sylivia Chematui Chesebe,
Virginia Nyambura Nganga
|2 May 2015||Nassau|
|6||10:45.32||Poland||Katarzyna Broniatowska, Monika Szczęsna, Angelika Cichocka, Sofia Ennaoui||2 May 2015||Nassau|
|7||10:46.94||Australia||Melissa Duncan, Samantha Lind, Brittany McGowan, Heidi See||2 May 2015||Nassau|
|8||10:48.38||Villanova||Kathy Franey, Michelle Bennett, Celeste Halliday, Vicki Huber||28 April 1988||Philadelphia|
|9||10:48.77 i||Oregon||Lilli Burdon , Ashante Horsley , Raevyn Rogers , Katie Rainsberger||27 January 2017||New York City|
|10||10:49.39 i||New Balance Europe||Lisanne De Witte , Esther Guerrero , Anna Silvander , Sarah McDonald||28 January 2017||Boston|