BackgroundFood insecurity during the COVID-19 pandemic has been impacted by necessary public health restrictions. Tasmania, an island state south of the Australian mainland, recorded no community transmission of COVID-19 between May 2020 to November 2021 due to strong border restrictions. This study aimed to determine the changes in prevalence and sociodemographic predictors of food insecurity throughout the COVID-19 pandemic in Tasmania, Australia.MethodsIn May 2020 (survey 1: during lockdown), September 2020 (survey 2: eased restrictions) and May 2021 (survey 3: 1-year post-lockdown), cross-sectional, online surveys using convenience sampling methods determined food insecurity in Tasmanian adults using the USDA Household Food Security Survey Module: Six-Item Short Form, in addition to key sociodemographic questions. Crude and age-adjusted prevalence of food insecurity was calculated, and binary logistic regression determined at-risk groups and changes in prevalence over time.ResultsThe age-adjusted prevalence of food insecurity was 27.9% during lockdown (n = 1168), 19.5% when restrictions had eased (n = 1097) and 22.6% 1-year post-lockdown (n = 1100). Young adults, Aboriginal and/or Torres Strait Islander people, individuals with disabilities, families with dependents and temporary residents were at highest risk across all time points.ConclusionsThe prevalence of food insecurity was higher than pre-pandemic levels across all three time points. Our results indicate the potential long-term impacts of the COVID-19 pandemic on food security in Australia, where despite easing social distancing restrictions and a lack of COVID-19 transmission, the prevalence of food insecurity reduced, but did not recover to pre-pandemic levels 1-year following a lockdown.