Microplastics are microscopic sized plastics. Microplastics are produced directly for cleaning and cosmetic products, and indirectly through the physical and chemical breakdown of larger plastic materials. These plastic particles can take thousands of years to fully decompose, and thus ultimately may end up in our waterways. Microplastics have been reported in the Ottawa and Rideau Rivers but little information exists on if these microplastics are being ingested by animals in these rivers. 150 invertebrates of classes Malacostraca and Bivalvia were collected from the Rideau River and 150 invertebrates of classes Malacostraca and Insecta from the Ottawa River. Nearly every single individual had microplastics in them, however there was no significant difference (p-value = 0.2641) in the number of invertebrates with microplastics in the Ottawa River versus the Rideau River. Microplastic concentrations were, however, significantly related to taxon (p-value = 2.67e-13) and weight (p-value < 2.2e-16).