Sea-level rise and storm events push saltwater landward (i.e., saltwater intrusion), driving changes in the chemistry, ecology, and greenhouse gas fluxes of terrestrial ecosystems. Present knowledge of the drivers and impacts of saltwater intrusion is based on temperate and tropical environments. Little is known about saltwater intrusion along Arctic coastlines where permafrost underlies coastal ecosystems. In this study, we investigate the drivers of coastal Arctic saltwater intrusion and the impacts of saltwater intrusion on porewater chemistry and greenhouse gas fluxes along Alaska’s Beaufort Sea coast. This work will provide baseline understanding of the physical, biological, and chemical processes occurring along rapidly changing Arctic coastlines.