Yellowtail Kingfish (Seriola lalandi) are a large, pelagic, highly mobile species of considerable commercial and recreational importance in Australia. The “Eastern Australia” stock, recognised to be genetically distinct from the West Australian population, spans several fisheries jurisdictions in southern and eastern Australia, however empirical movement data to inform stock structure at an ecologically-relevant time frame are currently limited. In this study, we describe distribution and connectivity of the Eastern Australia kingfish stock using over 40,000 tagged and released kingfish and 3,000 subsequent recaptures spanning 1973-2022 as part of the New South Wales (NSW) Game Fish Tagging Program, the world’s longest-lived, citizen-science saltwater recreational fishing tagging program. Broad-scale network analysis of 337 tagged kingfish revealed connectivity across five main bioregions across coastal and offshore southern and eastern Australia, as well as New Zealand (NZ). Connectivity also exists between state fishery jurisdictions, with extensive movements (n = 76) identified between NSW, South Australia (SA), Queensland, Victoria and NZ. Seasonal variability was evident in both releases and recaptures, with most states having a higher proportion of kingfish tagged and released in summer and autumn. Whilst spawning-sized kingfish (>83 cm fork length) were consistently caught and recaptured by recreational anglers in NSW waters, strong seasonality was evident for kingfish in SA, that exhibited both broad-scale connectivity with NSW as well as yearly spring availability in coastal SA. In contrast, juvenile kingfish (<50 cm FL) were mostly tagged in NSW and during summer months. Despite broad-scale coastal and offshore movements recorded, most individuals were recaptured within 5km and 60 days of their release location, indicating some degree of site fidelity. Our findings provide important new insights into the structure and connectivity of kingfish across eastern and southern Australian waters and highlights the need for multiple fisheries jurisdictions to collaborate in assessing and managing this stock.