<p>Monopile foundations, widely used for supporting Offshore Wind Turbines (OWTs) in shallow to medium water depths, are susceptible to seabed scour, which significantly compromises their lateral capacity and dynamic performance. This study investigates the dynamic response of offshore wind turbine monopile foundations under cyclic lateral loading, considering both global and local scour effects. A three-dimensional finite element model is developed in ABAQUS, incorporating a hypoplastic constitutive model with intergranular strain to capture the cyclic behavior of sand. The model is validated against centrifuge test data. Results show that global scour significantly increases pile head displacement and reduces lateral stiffness, while local scour mainly alters the failure wedge geometry. Considering scour-induced overconsolidation reduces the peak displacement by approximately 23% compared to the normally consolidated case. Parametric analysis reveals that increasing pile diameter improves stiffness but increases bending moment, whereas increasing wall thickness effectively reduces both displacement and bending moment. The influence of pile length is relatively limited due to the strong restraint provided by the bearing stratum. The findings highlight the importance of incorporating scour-induced changes in soil state and provide practical guidance for optimizing monopile design in offshore environments.</p>