Koosje van Voorn, (15 January 1935 â 5 August 2018) was a freestyle swimmer from the Netherlands. She competed in the 100 m and 4 à100 m relay events at the 1952 Summer Olympics and won a silver medal in the relay, alongside Marie-Louise Linssen-Vaessen, Irma Heijting-Schuhmacher and Hannie Termeulen.