Wetlands are ubiquitous within rapidly expanding urban areas, including naturally occurring relict wetlands, mitigation, “accidental wetlands,” and engineered constructed systems designed for stormwater storage and treatment. Our understanding of wetland biogeochemistry has largely been developed in non-urban settings. As researchers increasingly study urban ecosystems, evidence is emerging that the hydrology and geochemistry of urban aquatic ecosystems is very different from those in non-urban settings. The assumption that urban wetlands will function in similar ways to their rural counterparts may be inappropriate. Although a robust body of urban stream ecology theory has emerged (e.g., “Urban Stream Syndrome”), a similar coordinated effort and has not yet emerged for urban wetlands. Urban wetland conservation, management, and creation continues with minimal support from scientific studies to guide activities aimed at enhancing wetland biogeochemical function. This session will explore the unique biogeochemistry of urban wetlands from a variety of perspectives.