Karl Fleschen (born 28 June 1955 in Daun, Rhineland-Palatinate) is a retired West German runner who specialized in the 3000, 5000 and 10,000 metres.
He held the world record in the rarely contested 4 x 1500 metres relay (14:38.8 minutes with Thomas Wessinghage, Harald Hudak and Michael Lederer). In addition he still holds the German record in 25 km road race, with 1:13:58 hours from 1978.
He competed for the sports clubs LG Vulkaneifel and Bayer 04 Leverkusen during his active career.
| Year | Tournament | Venue | Result | Extra | |
|---|---|---|---|---|---|
| 1977 | San Sebastián, Spain | 1st | 3000 m | ||
| 1978 | Prague, Czechoslovakia | 13th | 5000 m | ||
| 1980 | Sindelfingen, West Germany | 1st | 3000 m | ||
| 1984 | Gothenburg, Sweden | 3rd | 3000 m |