Microplastic (<5 mm) pollution has increased on a global scale. However, we still know relatively little about how much plastic pollution is getting into Australia’s coastal oceans via rivers. In this study we provide the first assessment of the spatial distribution of plastics, the types of plastic and the total budget of sediments in Moreton Bay, Southeast Queensland. We collected a suite of surface sediment samples from Moreton Bay and analyzed them for microplastics (seven polymer types) using the Pyr-GCMS. The total plastic concentration varied significantly across the bay which was found to be unrelated to the mud content of the surface sediments and therefore may be influenced by the density of the plastic and the hydrodynamics in the bay. Similarly, it may also be affected by a range of sources, with some coming from the rivers, but others from local point sources in the bay. Polyethylene (used to produce plastic bottles and bays) was the highest concentration of plastic, followed by polyvinyl chloride with total concentrations ranging from 1.07 µg/g - 63.50 µg/g. Based on average microplastic concentration in the surface sediments we estimate that the total budget of plastic in the top 10 cm in the bay ranges from 300-400 tonnes.