Coastal zones are exposed to wave energy from site specific wave generation zones, which vary at different timescales in response to regional atmospheric variability, large-scale climate drivers and global climate change. Hence, the aim of this paper is to investigate the source and travel time of the wave energy reaching the East Australian Coast (from north New South Wales to Southeast Queensland) over last four decades. The ESTELA (Evaluating the Source and Travel-time of the wave Energy reaching a Local Area) methodology was used to (1) calculate the wave propagation pathways based on the great circle concept, then; (2) determine the frequency-direction distribution of the wave spectra and finally; (3) assess the effective energy flux to define the spectral energy travelling towards the target point near the coast. The results show two primary wave generation regions: directly to the east extending towards the central South Pacific Ocean within a 9-day wave travel time and to the south in the Tasman Sea along the southeast Australian coast within a 3- day wave travel time. Seasonal variability was detected with austral summer-autumn showing the highest wave energy, followed by winter and spring. The occurrence of strong La Niña events influenced more the wave energy within the 3-days travel time limit than El Niño episodes. Also, La Niña phases was observed to increase the easterly wave generation over all seasons by around 40% compared to the typical wave energy per season. Overall, this study presents a regional wave climate description that provides critical information for future coastal research and management as well as coastal recreation planning and harbour operations.