There is a notable paucity of research that has evaluated Internet Gaming Disorder (IGD) and smartphone addiction prevalence rates in children following the COVID-19 pandemic, including in Australian school-aged samples. The aim of the current study was to examine the prevalence and developmental impacts of IGD and smartphone addiction in children using a self-report survey design. A total of N=1993 Year 4-8 students completed the study. Medium to high smartphone addiction was found in 9.9% of the sample, whilst 4% of children met clinical (1.2%) or sub-clinical (2.7%) levels of IGD, with no differences across age ranges. A pattern of increasing developmental impacts for smartphone addiction and IGD was found. The greatest impacts on addiction and IGD were on emotional development and physical health development. These findings have implications for the increasing need for parent education, access to treatment services, and a focus on early intervention programs in primary school. (2024-05-23)