In response to the escalating global demand for sustainable energy and the environmental toll of fossil fuel dependency, this study presents a high-resolution Computational Fluid Dynamics (CFD) analysis of a Horizontal Axis Tidal Current Turbine (HATCT) designed for deployment in the Passur River, Khulna, Bangladesh, a region characterized by strong and predictable tidal flows. The CFD methodology is applied with a validated 3D turbine model, enabling precise evaluation of hydrodynamic performance metrics such as thrust, torque, and power output. The process supports optimization of blade geometry and operational parameters, contributing to the design of efficient tidal energy systems tailored to site-specific conditions. The turbine was tested across multiple mesh configurations to ensure numerical stability and mesh independence. Key findings indicate a consistent energy yield of approximately 3 kWh per tidal cycle, demonstrating the turbine’s viability for localized renewable energy generation. These results highlight the practical application of CFD in marine energy engineering and underscore the potential of HATCTs to support Bangladesh’s transition toward sustainable power infrastructure. The study offers a data-driven foundation for future experimental validation and large-scale implementation of tidal energy technologies in estuarine environments.