David Michael Rhys Davies (born 3 March 1985) is a Welsh competitive swimmer who has represented Wales at the Commonwealth Games, and swam for Great Britain at Summer Olympics, world championships and European championships, winning medals in each of those major international championships. Davies specialises in long-distance freestyle events. Born in Barry, Vale of Glamorgan, Davies swam for Wales at the 2002 and 2006 Commonwealth Games and represented Great Britain at the 2004, 2008 Olympics and 2012 Olympics. As of the end of 2010, he held the British Records in the 400-, 800- and 1500-metre freestyle events.
Davies represented Great Britain at the 2008 Olympics, swimming in both the pool competition and open water race. In the men's 1500m freestyle race, he finished 6th. In the open-water 10K race in Beijing, Davies finished second in the new Olympic event. Shortly after finishing the event, there was concern for Davies' state of health as First Aid staff rushed to stretcher him off for medical attention. Davies told the BBC shortly afterward: "For the last part of it I was delirious, I wanted it so bad. I've given it everything – the stretcher at the end was a bit mad but I've got something to show for it. I felt a bit violated to be honest, people swimming all over me, and the last lap was a real struggle.".