Provided is an apparatus for diagnosing a crack in a battery pack, and a battery pack and a vehicle including the same. The apparatus includes a sensing unit configured to generate a vibration signal indicating time-dependent changes in vibration of the battery pack and a processor. The processor generates spectral density data using the vibration signal. The processor detects a plurality of peaks from the spectral density data, and diagnoses whether the battery pack is cracked or not based on the plurality of peaks.