Arsenic (As) is a naturally occurring metalloid that can pose serious health risks through chronic environmental exposure, particularly when associated with contaminated soils or edible fungi. This study evaluated As concentrations in 850 surface soil samples and 106 wild mushrooms collected across urban Leicester and rural Bradgate Park (Leicestershire, UK) using ICP-MS. Arsenic was detected in 78.9% of soil samples and 34.9% of mushrooms, with significantly higher concentrations at urban sites, particularly in areas with known historical industrial activity and high traffic density. Median As concentrations were 8.4 µg/g in soil and 0.212 µg/g dry weight in mushrooms. Although bioconcentration factors (BCFs) calculated for As were relatively low (median BCF < 0.02), they varied between fungal species, suggesting differential uptake dynamics. Human health risk assessments for children and adults exposed via soil ingestion, dermal contact, and inhalation indicated that total hazard indices remained below the safety threshold of 1. However, ingestion accounted for the largest proportion of exposure across all groups, particularly among young children. The findings highlight the utility of combining soils and wild mushrooms as complementary matrices in urban environmental monitoring. However, current exposure levels do not pose immediate health risks; the persistence and potential carcinogenicity of arsenic support the need for routine surveillance in urban ecosystems and increased public awareness regarding foraging and home gardening. The study underscores the importance of integrated biomonitoring approaches to inform evidence-based public health strategies in contaminated or transitional urban landscapes.