AbstractObjectiveTo assess the longitudinal trends in social inequalities in early childhood caries (ECC) using collected population‐based data.MethodsClinical data on children were routinely collected from 2008 to 2019 in Victoria, Australia. ECC prevalence and severity (dmft) were quantified according to Indigenous status, culturally and linguistically diverse (CALD) status, concession cardholder status, geographic remoteness and area deprivation. The inverse probability weighting was used to quantify social inequalities in ECC. The weighted prevalence differences, and the ratio between the weighted prevalence of ECC and mean dmft and their 95% confidence interval, were then plotted.ResultsAbsolute inequalities in ECC prevalence increased for children by 7% for CALD status and cardholder status between 2008 and 2019. Likewise, absolute inequalities in ECC severity in this time period increased by 0.6 for CALD status and by 0.4 for cardholder status. Relative inequalities in ECC increased by CALD (ratio: 1.3 to 2.0), cardholder status (1.3 to 2.0) and area deprivation (1.1 to 1.3). Relative inequalities in severity increased by CALD (1.5 to 2.8), cardholder (1.4 to 2.5) or area deprivation (1.3 to 1.5). Although children with Indigenous status experienced inequalities in ECC prevalence and severity, these did not increase on the absolute (ECC: 0.1–0.1 Severity: 1.0–0.1) or relative scale (ECC ratio: 1.3–1.3 Severity ratio: 1.6–1.1).ConclusionsTrends in inequalities in ECC were different according to sociodemographic measures. Oral health policies and interventions must be evaluated on the basis of reducing the prevalence of oral diseases and oral health inequalities between population sub‐groups.