Energy resource classification systems are useful assessment tools, supporting energy planning and project development, e.g., siting and feasibility studies. They typically establish standard classes of power, a measure of the opportunity for energy resource capture. In this study, we develop wave energy resource classification systems based on wave power (J, kW/m) and its distribution with peak period (??, s). These metrics are calculated from partitioned bulk wave parameters generated from a validated 30-year WaveWatch III model hindcast. The classification systems, comprised of four power classes and three peak period band classes, are based on the total wave power or the partitioned wave power in the dominant peak period band. They provide useful information for a variety of stakeholders including energy planners, project developers, and technology designers. Further characterization is done by calculating the attributes of wave energy resource: spectral width, energy-weighted period, directionality coefficient, inter-annual variability, and monthly variability. As an example application for the United States coastal waters, computed marginal and joint energy distributions of the wave resources energy in terms of the peak period, wave direction and month and corresponding resource attributes are compared for two different wave climate regions.