Abstarct: In this study a numerical model has been created that can model overtopping of water waves with any desired initial conditions, using Smoothed-Particle Hydrodynamics (SPH). Smoothed-Particle Hydrodynamics is a lagrangian meshless particle baxsed method that can numerically model high deforming waves with high precision. Different approaches have been used up until now to estimate and model the magnitude of wave overtopping over shore walls, dykes, and other shore protection structures. In this study SPH is used to improve the precision and eliminate the weaknesses of these models. To simulate free-surface flows in Lagrangian Navier-Stokes equations, fluid particles are followed in numerous time-steps. In this study first the problem of a solitary-wave run-up is verified by comparing results from the numerical model to a lab model, and a good match was observed between the lab and the present models. Then the problem of a solitary-wave overtopping was modeled and the results were compared with lab data. It should be noted that particles are minified to 0.006 meters, and in some models more than 30000 particles are present which have made the results more accurate. Obtained results show that the present SPH model, is a convenient model for simulating complex fluid mechanics problems with free-surface boundary conditions.