Coastal regions have become essential as the backbone of the coastal areas for economic growth. Many coastal structures, both offshore and onshore, have emerged along these coastlines. However, the sudden occurrence of the natural calamities, such as severe storms, tsunamis, and rising sea levels, has developed significant heavy wave loads impacting these structures, leading to unexpected hazards and risks. As a result, ensuring the stability of onshore structures and their foundations under wave loading has become a critical concern. Despite considerable research into interactions between waves and structures, this concern remains a complex and critical challenge in coastal engineering. This project addresses this issue through a comprehensive numerical analysis of wave interactions with onshore and coastal structures using multiphase models within Computational Fluid Dynamics (CFD) tools. The study incorporates a Wave-Structure Interaction (WSI) approach that simulates the complex dynamics between incoming waves and coastal structures. The seabed profile of the seawall construction in Chellanam, Kerala, serves as a reference for this analysis. Keeping wave height constant, the study attempts to investigate the changes in pressure and velocity across different water depths and wavelengths. The main aim of this study is to initiate the analysis of these characteristics’ effects on onshore constructions, thereby providing insights that can be included in the design parameters of landward structures through an analytical framework.