A study on the relationship between levelized cost of energy (LCOE), its components, and terrain complexity was conducted for Korean onshore wind farms. The 22 wind farms are selected for this study. The actual capital expenditures (CapExs) and operational expenditures (OpExs) of the wind farms are collected from the Data Analysis Retrieval Transfer (DART) system of the Korean Financial Supervisory Service. The capacity factors (CFs) of the wind farms are estimated using the dataset of system marginal price (SMP), renewable energy certificate (REC), and capacities of wind farms. To evaluate terrain complexity, the ruggedness index (RIX) is calculated using the installed wind turbine locations of analyzed onshore wind farms and the numerical terrain contour data. The average RIX is 25.53% that corresponds to mountainous terrain. The correlation analysis is performed to determine the relationship between CF, CapEx, and OpEx in accordance with RIX. The LCOE is calculated from the actual expenditures and estimated CFs. Consequently, the average LCOE is estimated to be 141.04 USD/MWh. The correlation analysis reveals no relationship between LCOE, its components, and RIX.