Heavy metal contaminants in agricultural environments have received global attention due to their persistent effects on ecosystems. In this study, contamination levels as well as carcinogenic and non-carcinogenic health risks of 10 heavy metals on humans from 10 agricultural farm settlements in Odo-Oba, SW Nigeria, were assessed. The inductively coupled plasma mass spectrometry method was used to obtain the heavy metal constituents (HMC) of Cu, Pb, Cr, As, Zn, Cd, Ni, Sb, Co, and V at topsoils (approximately 25 cm depth) of the farms. The decreasing trend of the HMC is in the order of Cr > V > Zn > Pb > Ni > Co > Cu > As > Sb > Cd. The range of the HMC obtained indicated that Cr and V surpassed the approved limits of 100 mg kg−1 each, while the maximum range of Co should be under check as it is nearly close to the threshold limit of 20 mg kg−1. The pathway for contamination for adults and children in the study sites is of the order inhalation < ingestion < dermal. The non-carcinogenic health hazards for adults and children are 2.37 × 10−1 and 1.57 × 100, indicating a threat for children via dermal pathway (since the non-carcinogenic hazards>1). The carcinogenic health indices are 4.58 × 10−4 for adults and 3.12 × 10−3 for children, indicating a threat to all ages (since the carcinogenic indices > 10−4) as prescribed by USEPA.