The establishment of Aedes albopictus poses a risk of arboviral diseases, particularly Zika virus (ZIKV) infections, which belong to the Flavivirus genus. The first vector-borne transmission of ZIKV by Aedes albopictus in Europe was identified in Hyères, in the Var department of France. There were three cases, with symptoms beginning in early August 2019, all residing in the same neighborhood. A seroprevalence survey was conducted to determine the extent of local transmission and the proportion of asymptomatic and oligosymptomatic infections. In November 2019, capillary blood samples, information on medical history, and details regarding risk exposures (travel, mosquito bites) were collected from consenting residents and workers exposed to the vector within a 200-meter radius of the cases. Markers of flavivirus infection (Zika, dengue, and West Nile) were screened for using IgM and IgG ELISA serology; positive serum samples were then confirmed by seroneutralization (allowing for characterization of the antibody response and identification of a history of ZIKV infection). The survey was conducted in 61% of households in the study area (88/145), and samples were collected from 86% of eligible individuals surveyed (162/189). This percentage was 82% among workers (69/84). Eight individuals tested positive for anti-flavivirus IgG. The 5 seroneutralization tests performed showed no history of Zika virus infection. The other 3 individuals had previously lived in areas at risk for arbovirus transmission. This cluster of 3 ZIKV infection cases identified in Hyères remained limited, and the seroprevalence survey did not identify any additional cases.