A bass drum damper and a bass drum are provided. The bass drum damper includes a sound insulating plate that covers a batter head of an acoustic bass drum generating a percussive sound when a beater of a foot pedal percusses a predetermined percussion location. The sound insulating plate includes a contact portion having an opening portion open for the percussion location for the beater and is in contact with the batter head, and a fixing portion provided at a circumferential edge of the contact portion and fixed to a hoop applying a tensile force to the batter head, or the batter head. At least a part of the contact portion which is in contact with the batter head when not being percussed is separated from the batter head at a time of percussing of the beater and is brought into contact with the batter head again after percussing.