This study attempts to stabilize the heavy metals present on spent fluid catalytic cracking (FCC) catalysts in the marine clay matrix and produce value-added high strength bricks through a sintering process. Experimental results showed that the resulting bricks had high unconfined compressive strength ranging between 20.0 N/mm(2) and 92.0 N/mm(2) for marine clay-spent FCC catalyst samples and low-water absorption values ranging between 4.8 wt% and 18.5 wt%, as well as low metal leaching rates with metal concentrations ranging between 0.1 mg/l and 6.6 mg/l for vanadium and between 9.5 mug/l and 52.8 mug/l for nickel. It is believed that the stabilization process can be achieved in 2 ways: incorporation, in which the heavy metals form chemical bonds with the surrounding matrix to become part of its crystal structure, and encapsulation, in which a physical barrier is formed around the heavy metals, preventing them from leaching into the environment.