A piezoelectric actuator includes a piezoelectric element that includes a piezoelectric unit including a ferroelectric, which has an asymmetric bipolar P-E curve, a capacitor connected to the piezoelectric unit in series, and a resistor connected to the capacitor in series and connected to the ferroelectric in parallel; and a drive unit that inputs a drive waveform Vd, which includes a DC offset component of which polarity is opposite to polarization of the ferroelectric, to the piezoelectric element to drive the piezoelectric element. A value of a coercive electric field Ec1, a value of a coercive electric field Ec2, the capacitance Cs of the capacitor, the capacitance Cpz of the ferroelectric, combined resistance Rp of the resistance of the resistor and the resistance of the ferroelectric, and a fundamental angular frequency ω of the drive waveform satisfy Expressions I to III, wherein 1 / 3 ≦  Ec 1 + Ec 2  /  Ec 1 - Ec 2  Expression ⁢ ⁢ I C s ≥ 1.5 ⁢ ( C pz + 1 ω ⁢ ⁢ R p ) Expression ⁢ ⁢ II R p ≥ - 15 C s + C pz · 1 ln ⁡ ( 0.5 ⁢ ( C s + C pz ) C s ) . Expression ⁢ ⁢ III