Soil heavy metal contamination represents one of the most pervasive environmental and public health challenges confronting Nigeria’s agricultural sector. This comprehensive review synthesises published data from 2020 to 2025 on the spatial distribution of key heavy metals, lead (Pb), cadmium (Cd), chromium (Cr), arsenic (As), nickel (Ni), mercury (Hg), and copper (Cu), in Nigerian agricultural soils, their transfer into staple food crops, and the resultant human health implications. Evidence indicates that mean soil concentrations of Cr (81.77 mg/kg), Pb (19.91 mg/kg), As (13.23 mg/kg), and Cd (3.25 mg/kg) routinely exceed WHO/FAO permissible limits in many agroecological zones, with the Niger Delta, Kano metropolis, and Kwara State emerging as particularly vulnerable hotspots. Principal contamination drivers include petroleum extraction and oil spills, indiscriminate wastewater irrigation, excessive use of agrochemicals, artisanal mining, and tannery effluents. Bioaccumulation in staple food crops, including rice, cassava, yam, pumpkin leaf, spinach, and maize, confirms a functional soil-to-food contamination pathway with documented exceedances of Codex Alimentarius and European Union limits for Pb and Cd. Children and subsistence farmers represent the most vulnerable population segments through combined dietary and dermal exposure routes. Remediation strategies, including phytoextraction, biochar amendments, lime stabilisation, and microbial bioremediation, are critically evaluated. Policy gaps in regulatory enforcement, environmental monitoring, and food safety governance are identified. The review concludes by proposing an integrated, multi-stakeholder framework for sustainable soil management and food safety assurance in Nigeria.