In this paper, the effect of an Offshore Wind Farm (OWF) on the surrounding wave field is numerically investigated in frequency domain, using a BEM numerical model based on the potential flow theory. The analysis is performed for regular waves of various periods and incident wave directions and for irregular waves with variable peak period and significant wave height. Specific cases of regular and irregular waves are compared, revealing the differences between the regular wave model and the real sea state. By numerically simulating the incident wave and the scattering effects caused by the OWF, indications are provided regarding the impact of the OWF on the local wave climate.