Alexander Dale Oen (Norwegian pronunciation: [?l?k's?nd?r 'd??l? 'u??n]; 21 May 1985 – 30 April 2012) was a Norwegian swimmer.
He represented the clubs Vestkantsvømmerne (1995–2010) and Bærumsvømmerne (2011–2012).
Dale Oen's gold at the 2008 European Championships made him the first Norwegian male to win a medal at a major international long course championship.
Dale Oen got his international breakthrough in 2005, placing seventh in the 100-metre breaststroke during the 2005 World Aquatics Championships.
During the European short-course Championships in December the same year, he swam the 100 m breaststroke in 59.05 seconds, placing fourth and setting a new Nordic Record.
He became the first Norwegian to swim this distance in less than 1 minute.
At the Norwegian Short Course Championships two months later, he bettered that time to 58.81, a world best mark for the year.
On 30 April 2012, at around 19:50 MST Dale Oen was found unconscious in his hotel bathroom after having suffered a heart attack, caused by chronic, undetected coronary heart disease, a rare disease for a person of his age and fitness.
He was found in his bathroom by one of his teammates, and CPR was performed before Dale Oen was brought to Flagstaff Medical Center.
He was pronounced dead at 21:00 MST.
Dale Oen was attending a training camp with the Norwegian swimming team in Flagstaff, Arizona at the time of his death.