Born in Edam, North Holland, Netherlands, he won the speed skating title in his only World Championship competition in 1905 in the city of Groningen, Groningen province, Netherlands. He faced only three other skaters, one of whom was Martinus Lørdahl from Norway, who won the 500-meter race. After that, De Koning won all three remaining distances, thus claiming the title. De Koning participated in the 1904 and 1905 European Championships and the 1903, 1905 and 1912 Dutch Championships, winning them all. He set National Records in 1905 in the 500-meter and 10,000-meter races. These records were broken in 1926 and 1929. Coen de Koning is also famous for winning the Elfstedentocht twice, in 1912 and 1917.
"History" (in Dutch). Vereniging De Friesche Elf Steden [Association of the Eleven Fries Cities]. Retrieved 2010-09-26.
* Women were first allowed to take part in the tour proper in 1985; before then they had to skate with the amateurs and no award was given.
** After shared wins in 1933 and 1940, when the front-runners decided not to compete but join hands to cross the line together, this practice was forbidden by the organisation. Jan van der Hoorn, Aad de Koning, Jeen Nauta, Maus Wijnhout and Anton Verhoeven however ignored this rule when they crossed the finish line in unison. They were not disqualified, but no winner was declared.
"3,000 Skaters in 124-mile race" The Times (London). Wednesday, 31 January 1940. (48527), col B, p. 7.