This study investigates the development and characterization of ceramic rod-reinforced TWIP (twinning-induced plasticity) steel matrix composites, produced using the lost foam casting technique. Mechanical tests revealed a substantial improvement in both flexural strength and ductility, with the composite demonstrating more than double the strength of unreinforced TWIP steel. Furthermore, a simple low-temperature heat treatment further enhanced these properties, increasing the flexural strength of the composite to 1023 MPa while also improving its ductility. The improvement in mechanical performance is attributed to the formation of additional twins in the TWIP steel matrix during deformation following heat treatment, which resulted in further strengthening of the matrix.