The wave energy resource of the SE Bay of Biscay is investigated using wave buoy data and a hindcast data set covering a 44-year period (1958–2001). Of the total 13 study sites, three correspond to wave buoys (two coastal, one in deep-water) and the rest to hindcast data points. First, the resource is quantified—annual wave energy is found to exceed 200 MWh m−1 at all the sites (with the exception of the coastal buoys), and average wave power is in the region of 25 kW m−1. This substantial resource is the result of the Bay of Biscay’s position at the eastern end of the Atlantic Ocean together with the wind regime of the mid-latitudes (prevailing westerlies). Second, the resource is characterised in terms of sea state parameters. The bulk of the annual wave energy is provided by waves with significant wave heights of 1.5–4.0 m, energy periods of 10.5–13.5 s, and mean deep-water direction NW–WNW. Finally, wave interaction with the irregular bathymetry gives rise, in certain nearshore areas, to significant concentrations of wave energy. These hot spots have the highest potential as prospective wave farm sites; their locations are determined using numerical modelling.