Simon Ketellapper was a son of Isaäc Ketellapper and Leentje Frinkel. He married 4 January 1939 in Amsterdam to Marianne Schelvis, a daughter of Arie Schelvis and Elsje Polak.
Simon was the brother of Rachel, Jetje and Marcus.
Amsterdam City Archives, records of Isaac, Marcus and Simon Ketellapper .
In addition, Jokos files (numbers 50623, 51523) on this family or other family members are at the Amsterdam Municipal Archive. Access is subject to authorization from the Stichting Joods Maatschappelijk Werk.