Results from the WAVEWATCH III simulation by the Geospatial Information Agency of Indonesia are used to describe the characteristic and variation of wind-driven waves and its energy throughout Indonesian seas and adjacent waters for 25 years (1991–2015). The simulation results are compared with buoys and Topex/Poseidon satellite observation to test the model reliability on the specific sites and regional scale. The annual average of Significant Wave Height (SWH) and its energy are presented along with monthly average of wind speed, SWH, and wave energy to describe the monthly variation across the year. In addition, the extreme environment analysis is presented through the percentile statistics of SWH and wave energy. In order to determine the suitable sites for wave energy converter installation, an overview using the index of Coefficient of Variance, Monthly Variability Index, Optimum Hotspot Identifier, and Wave Development Index is employed. Subsequently, the power rose and SWH state of the wave energy from 20 different sites representing the Indonesian seas and adjacent waters are analyzed. The study aims to illustrate the wave climate and its energy potential using the long-term open access data set available within the scope of Indonesian seas and adjacent waters.