The NSW state-wide threat and risk assessment and the more targeted marine debris threat and risk assessment, identified microplastics as a significant and emerging issue for the NSW marine estate, and a threat to its social and environmental assets. Consequently, addressing microplastic pollution is an emerging priority for government and natural resource managers. A key impediment to effective management of microplastic pollution relates to a lack of data on the distribution, abundance, and source of microplastics within NSW. This study addresses some of these identified knowledge gaps by providing a spatial risk assessment of microplastic contamination across NSW estuaries. As part of the study, a targeted local scale microplastics study is underway in the iconic Sydney Harbour, with the aim to identify priority source sub-catchments and potential source land-use types. Here, we present a spatial assessment for microplastic contamination across the state and in Sydney Harbour’s surface waters. Preliminarily findings across its three main tributaries found density of microplastics (MP) varied. Parramatta River had the highest concentration (2.7 MP/m3), Middle Harbour an intermediate amount (2.1 MP/m3), and Lane Cove River had the lowest (1.1 P/m3). Further analysis is required to determine land-use type as a predictor of microplastic load. Both Lane Cove and Middle Harbour tributaries had a lower abundance of polymer type (10 polymers) when compared to Paramatta (20). Microplastic contamination in the main basin of the estuary, Port Jackson which has more ocean influence, was the lowest across all surface waters sampled in Sydney Harbour (0.6 MP/m3), suggesting dilution and loss of microplastics to estuarine outflows and tidal exchange. Investigating microplastics on a local and broader catchment scale in the context of land-use types fills key knowledge gaps on spatial distribution, abundance, and source in NSW.