Benjamin van Kleef was a son of Hartog van Kleef and Judith Noot. He married Henriette de Leon in Amsterdam on 3 September 1919, a daughter of Salomon de Leon and Heintje Jas. The couple had two daughters: Judith and Hendrika, who both got married in May and July 1942. Hendrika however survived the Holocaust.
City Archive of Amsteram, archive cards of Benjamin van Kleef and Henriette de Leon.