Over the past century, oyster reefs have faced significant degradation on a global scale. As oyster reef restoration continues, the optimisation of these efforts is needed to enhance the effectiveness of rehabilitation programs around the world. This study identified how the characteristics of oyster reef patches and connectivity of oyster reef systems influenced three key fish assemblages metrics on oyster reefs (abundance, diversity, richness). Fish communities were surveyed in three natural remnant oyster reefs throughout NSW in summer and winter from 2019-2021 using underwater remote video to determine the influence of reef characteristics on our key metrics. The response of fish assemblages to reef characteristics varied significantly depending on the estuary, season, and reef zone. However, there were some consistent patterns which suggest that a reef system containing multiple smaller discrete reef patches, circular in shape with high levels of patch connectivity and surface complexity, has a greater potential to support a highly biodiverse and abundant fish community compared to systems composed of larger, more continuous reef patches. The findings from this study may aid in increasing the efficiency and efficacy of restoration programs and their ability to support diverse fish communities in estuaries within NSW and worldwide.