Heavy metal contamination of seafood poses potential ecological and human health risks, particularly in coastal regions affected by intense anthropogenic activities. This study evaluated the concentrations of essential and toxic heavy metals in selected fresh and smoked seafood obtained from the Kaa coastal market in Rivers State, Niger Delta, Nigeria, and assessed the associated health risks from dietary exposure. A total of sixty seafood samples comprising three finfish species (Oreochromis niloticus, Pseudotolithus elongatus, and Clarias gariepinus) and three shell seafood species (Callinectes amnicola, Tympanotonus fuscatus, and Penaeus notialis) were collected in both fresh and smoked forms. Samples were digested using nitric–perchloric acid digestion and analyzed for Fe, Zn, Cu, Mn, Pb, Cd, Hg, As, Cr, and Ni using Atomic Absorption Spectrophotometry. Iron concentrations ranged from 33.2–38.5 mg/kg in fresh fish and 40.8–46.1 mg/kg in smoked fish, while shell seafood recorded 37.4–42.3 mg/kg (fresh) and 45.2–49.6 mg/kg (smoked). Lead concentrations varied from 0.27–0.34 mg/kg in fresh fish to 0.36–0.41 mg/kg in smoked fish, with shell seafood reaching 0.44 mg/kg in smoked samples. Estimated daily intake values were higher for children (1.54×10⁻³ mg/kg/day) compared with adults (3.3×10⁻⁴ mg/kg/day). Hazard index values ranged from 0.94–1.09 in fresh fish to 1.27–1.81 in smoked seafood, indicating possible non-carcinogenic risks with prolonged consumption. Carcinogenic risk values ranged from 2.3×10⁻⁴ to 4.6×10⁻⁴, largely driven by arsenic exposure. The results indicate that smoked seafood and shellfish may present higher heavy metal exposure risks. Continuous monitoring of seafood contamination and environmental pollution control are recommended to protect public health in coastal communities of the Niger Delta.