<p>Microplastics (MPs), abundant in marine ecosystems, are ingested by filter-feeding bivalves. In Nova Scotia, Canada, Blue mussels (<i>Mytilus edulis</i>) and Eastern oysters (<i>Crassostrea virginica</i>) are economically important mariculture species yet their exposure to MPs remains poorly recognized. In this study, bivalves were collected from 13 locations across Nova Scotia. Mean MPs concentrations were 4.25 ± 1.48 SMPs g⁻¹ wet weight (ww) tissue (48.59 ± 17.93 MPs ind.⁻¹) in Blue mussels, and 3.79 ± 1.27 SMPs g⁻¹ ww tissue (53.54 ± 21.78 MPs ind.⁻¹) in Eastern oysters. ‘More anthropogenically influenced’ locations such as in Halifax or in proximity to shellfish aquaculture areas contained higher concentrations of MPs in both bivalves. In sites where mussels and oysters were co-located, concentrations of MPs were significantly higher in mussels suggesting physiological or anatomical differences which may influence MP uptake and accumulation. Fragments or films were the most common MP shape found both species. MPs were predominantly in the 2–10&#xa0;μm and 10–20&#xa0;μm size ranges in mussels and oysters, respectively. Polyethylene and polyvinyl chloride were the most frequently observed polymer types based on micro-Raman analyses in both species. Overall, MP concentrations and sizes measured in bivalves in this study were within the range of values reported from studies that demonstrated harmful effects to individuals such as oxidative stress and impacts to metabolism. Future studies exploring ingestion of MPs in wild and farmed bivalves, as well as species differences are recommended.</p>