Arctic coasts are increasingly exposed to sea-level rise, wave-driven flooding, and rising ocean temperatures. In temperate zones these factors are known drivers of lateral and vertical seawater intrusion into coastal aquifers. In permafrost regions, however, coastal aquifer salinization has not been widely investigated even though the potential impacts on subsurface thermal regimes, permafrost distribution, and groundwater processes have been recognized. We integrate geophysical surveys, in-situ porewater salinity and ground temperature measurements, and analytical modeling to investigate how coastal morphology, stratigraphy, and oceanic forcing govern distributions of subsurface salinized zones and frozen ground along an Arctic shoreline. Fieldwork occurred during the summers of 2023 to 2025 at contrasting coastal sites near Cambridge Bay (NU): one narrow beach backed by an eroding coastal bluff, one wide, prograding linear beach, and another wide beach shaped to a point by converging waves. Subsurface electrical conductivity distributions reveal groundwater flow paths and salinity patterns influenced by stratigraphy and beach morphology, the latter regulating overland wave-driven flooding. Sites with wider swash zones appear to have an upper saline plume, unlike the narrower bluff-backed site. High porewater salinity and resultant freezing point depression also allows for a larger zone of unfrozen porewater than would occur for the same sub-zero temperatures if the porewater was fresh. This results in a longer period through the winter when groundwater transport and unfrozen sediment mobilization may occur, which are critical considerations when assessing the vulnerability of Arctic coasts to climate change-driven hazards such as erosion or contaminant transport.