Listeria monocytogenes (Lm) is a pathogenic bacteria responsible for listeriosis, which is transmitted mainly via the food chain. The characterization of strains isolated from the agri-food chain contributes to a better understanding of their ecology, and to the assessment of food-related health risks. In this frame, the National Reference Laboratory for Listeria monocytogenes (NRL) has been committed since 2019 to the systematic genomic characterization of strains isolated from official controls. This article describes the organization set up for this characterization and presents the results obtained over the 2019-2021 period. Out of six major food categories, the strains are divided into four serotypes and 83 clonal complexes (CC). These descriptive results show that CC121 and CC9 are predominantly isolated, as described in the literature for food-borne strains. They also identified genomic clusters suggesting the persistence of Lm strains in certain processing or storage sites, as well as the presence of strains associated with hypervirulence in different types of ready-to-eat foods of plant or animal origin. The conclusions highlight areas for optimizing the genomic surveillance of Lm in foodstuffs, involving the network of official laboratories supervised by the NRL, and underline the importance of interactions with the National Reference Centre Listeria (NRC) in charge of alerts and surveillance of cases of human listeriosis, to ensure the most exhaustive possible view compatible with risk management.