Koen Leenhouts is a Dutch chess grandmaster.

In April 2012, he won the Zeeland Rapid Open tournament, finishing with a score of 3 points over second place.

[2] In August 2017, he tied for first place with Sandipan Chanda at the Netherlands Open, but was ranked in second place due to tiebreaks.

[3] This secured him his first GM norm.

[4] In April 2023, he achieved his final GM norm at the Belgian Interclubs; the same tournament in which he achieved his second GM norm.