A piezoelectric device and a display apparatus including the same are provided. A piezoelectric device includes: a first piezoelectric unit including a vibration-generating layer configured to vibrate at an input frequency based on a sound signal corresponding to the input frequency, and a second piezoelectric unit including: an air gap in the first piezoelectric unit, the air gap having a certain volume, and an air path connecting the air gap to an outer portion of the vibration-generating layer, the air path being configured to output a vibration.