Using standard operant conditioning techniques, a killer whale,Orcinus orcaLinnaeus, was trained to respond to pure‐tone auditory signals by pushing a response manipulandum. An audiogram was obtained for frequencies between 500 Hz and 31 kHz. Greatest sensitivity to the signal was observed at 15 kHz at a level of −70±5 dBre1 dyn/cm2. The observed upper limit of hearing was 32 kHz. At no time during training or testing did the animal respond to an undistorted signal above 32 kHz. Frequencies below 500 Hz were not tested, owing to high ambient tank noise levels.