Salomon de Jong was a son of Marcus Salomon de Jong and Rachel Koen. He married 20 December 1927 in Bialystok (Poland) Szosza Mandelbaum from Grodno. The couple had a daughter, born in Amsterdam in November 1933, who has survived the Holocaust.
Salomon had a sister who has survived the Shoah too and a sister Sara, who has been killed in Sobibor on 11 June 1943. Salomon self lost his life on 4 February 1945, somewhere in Mid Europe, after he was registered in transit camp Westerbork on 20 June 1943 and deported "Eastwards" (Auschwitz?) on 23 March 1944. His wife Szosza was sent to Auschwitz on 15 November 1943 and killed there on 31 January 1944.
City Archive of Amsterdam, archive cardss of Marcus Salomon de Jong, Salomon de Jong and Szosza Mandelbaum and the File Cabinet of the Jewish Council of Amsterdam, records of Salomon de Jong and Szosza Mandelbaum.