Parvovirus B19 (B19V) is a DNA virus with a global reach. Infection results in a variety of clinical presentations, including erythema infectiosum in children and arthralgia in adults. Transmission is usually through the respiratory route, however, vertical transmission, transfusion-transmission, as well as transmission through solid organ or haematopoietic transplantation, have been documented. There is limited understanding of current seroprevalence of antibodies to B19V in the Australian population. This study aimed to provide a current estimate of B19V IgG seroprevalence in a cohort of Australian blood donors and in a pediatric population. Age/sex/region stratified plasma samples (n=2,221) were collected from Australian whole blood donors. Samples were also sourced from pediatric patients (n=223) in Queensland. All samples were screened for B19V IgG using indirect-based enzyme-linked immunosorbent assay. Overall 57.90% (95% CI: 55-94-59.85) of samples tested positive for B19V IgG, indicating prior exposure to this virus. The national age-standardized seroprevalence of B19V IgG in Australian’s aged 0 to 79 years was estimated to be 54.41% (95% CI: 54.39-54.43%). Increasing age (p<0.001) and state of residence (p<0.001) were independently associated with B19V IgG seropositivity in blood donors, while sex was not (p=0.547). A large amount of variation in B19V IgG prevalence between the states was observed, with the highest rate observed in donors from Tasmania (71.88%, 95% CI: 66.95-76.80%) and the lowest in donors from the Northern Territory (52.56%, 95% CI: 46.84-58.28%). This study demonstrates a clear association between B19V seroprevalence and increasing age, with over half of Australians likely to be immune to B19V. Differences in seroprevalence were also observed in donors from different states, with a higher prevalence in those from the southern states, which is consistent with previous studies that show higher rates in countries with a higher latitude. This study provides insight into the seroprevalence of B19V IgG in the Australian population, which has implications for public health as well as transfusion and transplantation safety in Australia.