Prediction of the dynamic performance of an offshore wind turbine (OWT) requires consideration of many different design parameters. Besides the superstructure, the OWT foundation also plays an important role both functionally and financially in the design. In this study, numerical dynamic analyses of an offshore wind turbine with a monopile foundation are performed under wave loading that may lead to soil liquefaction around the pile due to cyclic stresses induced by the pile displacements using the open-source program, OpenSees. Effects of foundation properties such as monopile diameter, pile embedment depth, and sea-wave characteristics such as its period, sea-water depth, duration, and level of the loading on the dynamic performance of the system are investigated. The results in terms of deformations, excess pore water pressure, and inertial forces are presented and discussed. The findings are considered as valuable guidance on the estimation of the dynamic performance and liquefaction susceptibility of the offshore wind turbine foundations under cyclic sea-wave loads.