<p>A coupled tide-surge-wave model was established to analyze the impacts of radial sand ridges on storm surges in the South Yellow Sea. Numerical topography experiments were designed on the basis of multiple well-verified types of extreme weather events. The findings demonstrated that the radial sand ridges (RSRs) generally enhanced tidal levels, current velocities, and significant wave heights in the affected area. The nonlinear effects of shallow water in the radial sand ridge area can induce large tide ranges. A unique seabed can cause an increase in current speed from the open sea to the nearshore. Another impact is that subaqueous ridges can result in shallow water conditions, and the degree of depth-induced wave breaking significantly varies. Compared with those in the northern and southern radial sand ridge areas, the tidal levels, current speeds, and wave heights in the middle radial sand ridge area were the highest, which can cause more severe storm surge disasters. Additionally, the wave radiation stress varied obviously under the action of fan-shaped sand ridges. Thus, it is necessary to consider wave-current interactions when modeling storm surges in sand ridges.</p>