Urban wetlands and stormwater ponds are widely incorporated in residential developments for stormwater management, integrated with green infrastructure elements with the main aim to serve as receptacles for stormwater runoff and mitigate the adverse impact of urbanization on water quality and quantity. Although urban wetlands and stormwater ponds provide important ecosystem services, the accumulation of organic matter and nutrients creates biogeochemical conditions that drive microbial processes and result in the emission of greenhouse gases (GHGs) such as methane (CH4) and carbon dioxide (CO2), through multiple emission pathways. CO2 is primarily released via diffusive exchange across the water–air interface, while CH4 is emitted through both diffusion and episodic ebullition from sediments. Hence, this study aimed to quantify GHG emissions from stormwater ponds and urban wetlands in the Kitchener-Waterloo region, Southern Ontario and assess the impact of selected environmental, physical and chemical variables on these GHG emissions. The average daily fluxes across the sampling period were 760 mg CO2 m-2 d-1 and 417 mg CH4 m-2 d-1. Methane emissions were dominated by ebullition, where ebullitive fluxes were three times higher than diffusive fluxes, accounting for approximately 68% of the total CH4 released across all ponds. For CO2, significant predictors included water temperature, pH, dissolved oxygen (DO), dissolved organic carbon and NO3- concentrations, and physical features including sediment depth, pond depth, catchment area and dredging. Methane emissions were primarily driven by in-situ environmental variables, including water temperature, DO concentration and pH, while chemical and physical factors did not significantly influence CH4 fluxes.