Disclosed is a piezoelectric actuator which has an improved driving force or drive efficiency. Specifically disclosed is a piezoelectric actuator which is provided with: a plurality of piezoelectric members which have a first piezoelectric element capable of being displaced in a first direction and a second piezoelectric element capable of being displaced in a second direction intersecting the first direction, and which are divided into a plurality of groups; a relative movement member which has a contact surface that is in contact with the piezoelectric members, and which moves relatively to the piezoelectric members in the first direction; and a drive unit which, when piezoelectric members of one group among the plurality of groups are in contact with the contact surface, drives the first piezoelectric element of the piezoelectric members.