Rapid environmental change in the Arctic has the potential to alter mercury (Hg) cycling and shape methylmercury (MeHg) transport across connected freshwater and terrestrial food webs. Freshwater ecosystems are important sources of MeHg, a potent neurotoxin, to terrestrial consumers, yet the degree to which this subsidy elevates Hg concentrations in terrestrial predators remains unclear in High Arctic landscapes. We quantified Hg concentrations in spiders and their potential prey at three distances from pond shorelines (0m, 10m, 35m) in six freshwater ponds in High Arctic Greenland to evaluate cross-ecosystem transfer of Hg and the role of distance from pond shorelines and trophic position in structuring exposure. Across all ponds, spiders consistently exhibited Hg concentrations elevated relative to their prey; however, these concentrations were not related to distance from shorelines, suggesting that spiders may be feeding on high-Hg prey far from the pond shorelines. Contrary to expectations that terrestrial insects would exhibit lower Hg concentrations than aquatic taxa, aquatic and terrestrial insects did not differ in overall Hg. Instead, Hg exposure within terrestrial insects was strongly structured by feeding guild, increasing with trophic position from nectivores to predators. Predatory terrestrial insects accumulated Hg concentrations approaching those of spiders, indicating substantial biomagnification occurring within the terrestrial invertebrate community. These results suggest that trophic position, rather than habitat (aquatic versus terrestrial), may be the primary determinant of Hg exposure in this High Arctic food web. Elevated Hg concentrations in terrestrial insects reveal an important pathway for contaminant transfer to terrestrial predators, with implications for consumers such as insectivorous birds that rely heavily on spiders and aquatic and terrestrial insects during the Arctic breeding season.