Colleen S. De Reuck (born 1964 in Vryheid, Kwazulu-Natal) is a long-distance runner from South Africa, who became an American citizen on 11 December 2000. She has had a long-lasting career, running in her forties, and made a total of four appearances at the Summer Olympics.
She won the USA Cross Country Championships twice consecutively in 2004 and 2005. De Reuck represented the United States twice more at the World Cross Country Championships, finishing in 13th place in 2005, and 33rd place at her final competition in 2006 at age 41.
At the 2009 Boston Marathon at age 45, she finished 8th overall, beating the W40 winner by over a minute and the next competitor in her own division by 14 minutes.[5] Just nine days earlier she had run 2:32:37 at the Twin Cities Marathon in St. Paul, Minnesota beating the listed American W45 record by over 6 minutes.[6]
She ran at the Falmouth Road Race in Massachusetts in August 2010 and took fifth place as the first American past the line.[7] Shortly after she ran in the Copenhagen Marathon in Denmark and placed 1st in 2:30:51, 8 minutes ahead of her nearest opponent.
On 14 January 2012, de Reuck ran in the 2012 US Olympic Team Marathon Trials, finishing in 2:38:52. Her pace was 13:14 behind women's winner Shalane Flanagan. Her time was good for a 35th-place finish out of 152.
Following her elite career de Reuck took up coaching with Boulder Striders as well as personal training. She was inducted into the Boulder (Colorado) Sports Hall of Fame in 2018.[8]