Wave energy converters (WECs) are built to extract wave energy. However, this kind of device is still expensive for commercial utilization. To cut down the cost of WECs by sharing the construction cost with breakwaters, an integrated cylindrical WEC-type breakwater system that includes a cylindrical WEC array in front of a very long breakwater is proposed to extract wave energy and attenuate incident waves. This paper aims to optimize the performance of the integrated cylindrical WEC-type breakwater system. A computational fluid dynamics tool, openfoam®, and a potential flow theory-based solver, HAMS®, are utilized. openfoam® provides viscosity corrections to a modified version of HAMS® in order to accurately and efficiently predict the integrated system’s performance. Parametric studies are conducted to optimize the integrated system, and a novel setup with an extra arc structure is found to significantly improve the performance of the integrated system.