As of January 1, 2023, the Aedes albopictus mosquito—a vector for dengue, chikungunya, and Zika viruses—was established in 71 departments in mainland France (including Corsica), exposing these areas to the risk of local transmission of these arboviruses. Epidemiological surveillance is adapted to the seasonal nature of this risk and is primarily aimed at preventing and/or limiting the establishment of a cycle of local transmission. In 2023, 2,524 imported cases of dengue, 44 cases of chikungunya, 11 cases of Zika, and one dengue-chikungunya co-infection were reported by healthcare professionals through mandatory reporting or detected through data from the network of partner laboratories. The majority of imported dengue cases had traveled to Guadeloupe and/or Martinique (71%, n=1,795). Nine episodes of local dengue transmission were identified, resulting in a total of 45 cases infected in mainland France. These episodes occurred in the Provence-Alpes-Côte d'Azur region (n=4), Occitanie (n=3), Auvergne-Rhône-Alpes (n=1), and Île-de-France (n=1). In 2023, the number of imported dengue cases was the highest recorded since the system was established in 2006, with the majority of cases returning from Guadeloupe and Martinique. The year 2022 had revealed a marked increase in the number of dengue transmission outbreaks and locally acquired cases in mainland France. The year 2023 confirms this trend, with the same number of outbreaks (n=9) and new departments affected, including one in Île-de-France, marking the first dengue transmission in such a northern region of Europe.