Metal overexposure is a significant public health concern, and children are particularly vulnerable due to their small body size, higher absorption rates, and immature metabolism. In Nigeria, dietary intake is a significant source of metal exposure, and there is a need to understand the extent of chronic metal overexposure in children. The aim of this systematic review is to identify and evaluate the existing evidence on chronic metal overexposure in children due to dietary intake in Nigeria. A systematic search was conducted in major databases, including PubMed, Research gate, Goggle scholar and Web of Science, to identify relevant studies published between 2012 and 2023. The search was restricted to studies conducted in Nigeria and written in English. A narrative approach was used to synthesize the findings from the selected studies. The search yielded a total of 32 studies that met the inclusion criteria. The studies included in this review reported on the levels of lead, cadmium, chromium, and arsenic in various food items and biological samples of children. The studies also reported on the health effects associated with chronic metal overexposure in children, including cognitive impairment, anemia, and renal dysfunction. The sources of metal exposure identified in the studies include contaminated soil, water, and food items, as well as occupational exposure in some cases. The findings of this systematic review indicate that chronic metal overexposure in children due to dietary intake is a significant public health concern in Nigeria. The sources of metal exposure are diverse, and the health effects associated with chronic exposure are severe. Therefore, there is a need for interventions to reduce the exposure of children to these toxic metals, including regulation of the use of pesticides and other chemicals, improved sanitation, and public health education. Further research is also necessary to better understand the extent of the problem and develop effective interventions.