Meijer Jacob Leons was a son of Isaac Leons and Barendina de Leeuwe. On 5 May 1886 he married Sara Boekbinder in Rotterdam, a daughter of Juda Simon Boekbinder and Lena Izaaks. The couple had eight children; their first born son Izaak passed away however at age 23 in 1909. All other children, namely Lena, Louis Abraham, Juda Simon, Barendina, Judith, Salomon and Abraham and their families have been killed in the Shoah.
During his working life Meijer Jacob was a messenger for a health insurance and a dealer. Since 1931 he has become widower as his wife Sara Boekbinder passed away on 10 March 1931 in Rotterdam. Meijer Jacob Leons himself died on 23 May 1941 and the funeral records at the Jewish cemetery in Rotterdam reveal that Meijer Jacob Léons was buried there.
City archive of Rotterdam, family registration card of Meijer Jacob Leons and the index of marriages of the Civil Registry of Rotterdam.