Wetlands are an integral part of the Canadian landscape, providing crucial ecohydrological services with globally significant benefits. Over the past 75 years, Canadian scientists have emerged as international leaders in wetland hydrological research, contributing to a better understanding of wetland form and function. Early Canadian research was instrumental in the development of a classification scheme that provided a foundation for later investigations into vadose zone processes, solute transport, evapotranspiration, ground-ice dynamics, biogeochemical cycling, and modelling. This work has coalesced into a better understanding of the factors that contribute to wetland presence and persistence on the landscape, and the internal processes that result in their unique functions of carbon sequestration, water storage, flood mitigation, water quality enhancement, and wildlife habitat. In Canada and across the world, wetlands are threatened at a range of scales and intensities by disturbances like climate change, resource extraction, wildfire, altered land use, and contamination. In response, Canadian researchers have become global leaders in characterizing the impacts of disturbance on wetland function and been at the forefront of innovative restoration and reclamation techniques. As the value of wetland is increasingly acknowledged by stakeholders and decision-makers, the need for evidence-based wetland research will only continue to grow. Canadian scientists are well-positioned to lead wetland hydrology into the next 75 years.