A display device that senses externally applied pressure and a change in the resonant frequency of a piezoelectric element. The display device includes a piezoelectric sensor layer including a piezoelectric sensor; and a display panel disposed on the piezoelectric sensor layer. The piezoelectric sensor includes: a piezoelectric element having a first electrode, a second electrode facing the first electrode, and a piezoelectric material disposed between the first electrode and the second electrode; an alternating current (AC) voltage generator connected to the first electrode and applies a voltage having a resonance frequency to the piezoelectric element. A sensing circuit connected to the second electrode is configured to measure a change in impedance of the piezoelectric element.