Understanding how animal growth varies in response to changing environmental conditions at different spatial scales can help predict population responses to global climate change and support the management of wild populations. Here, we assessed the growth response of black bream, Acanthopagrus butcheri, to environmental conditions in estuaries across southern Australia. Specifically, we investigated the large and small-scale spatial variability in growth patterns over a multi-decadal period using otolith growth chronologies and increasingly complex linear mixed-effects models to partition the effects of intrinsic and extrinsic factors (e.g., age, freshwater inflow, sea surface temperature, El Niño-Southern Oscillation). By constructing long-term ecological datasets, we were able to identify major drivers of growth variation across the species distribution range and highlight patterns in growth variability among heterogeneous estuaries and climatic regions. Our understanding of growth variability can support the sustainable management of exploited black bream populations while maximising their resilience to fishing and climate pressures. Overall, our findings provide a foundation to understand the drivers of growth variations in complex estuarine environments and can be a proxy for assessing similar estuarine dependent species.