Moisture damage remains one of the primary causes of premature asphalt pavement failure, leading to stripping and strength loss under prolonged water exposure. This study investigates the effect of using cement dust as a waste-derived filler compared to traditional limestone dust on the moisture susceptibility of asphalt mixtures. Both materials were selected based on their local availability and environmental benefits. A total of 30 Marshall specimens were prepared to determine the Optimum Asphalt Content (OAC) and were subsequently immersed in freshwater and sewage water for 28 days to simulate extended moisture exposure. Performance was evaluated through Marshall Stability and Indirect Tensile Strength (ITS) tests under dry and wet conditions. The results showed that mixtures containing cement dust exhibited higher stability and retained strength than those with limestone dust, confirming its superior resistance to moisture-induced damage. Overall, cement dust presents a sustainable and effective alternative filler for improving asphalt pavement durability.