Soils are generally rich in iron, the fourth most abundant element in Earth’s crust. Changes in the redox state of iron can be coupled to the biogeochemical cycling of carbon, nitrogen, and phosphorus through both biotic and abiotic processes. The importance of iron in catalyzing redox-driven biogeochemical cycling has been underappreciated in terrestrial ecosystems because they are not typically thought of as anaerobic environments. However, soils can experience anaerobic conditions following rainfall events or in microsites of high biological oxygen consumption. The goal of this session is to bring together researchers from a range of backgrounds (e.g., geochemistry, microbiology, ecology, biogeochemistry) to highlight novel processes that couple iron cycling to carbon, nitrogen, and phosphorus cycling as well as explore the mechanisms that may control these interactions.