An ultrasonic actuator may be provided in which generation of a stress is prevented in the connection face of the piezoelectric element between the electrodes and the conductive members. The ultrasonic actuator includes a piezoelectric element (P1) and flexible cables (F1). The piezoelectric element (P1) includes: a piezoelectric layer (1); a power supply electrode (2) provided on a principal surface of the piezoelectric layer (1); a counter electrode (3) provided to face the power supply electrode (2) with the piezoelectric layer (1) interposed therebetween; a power supply external electrode (4) which is provided on a short-side surface of the piezoelectric element (P1), and is electrically coupled to the power supply electrode (2); and a counter external electrode (5) which is provided on a short-side surface of the piezoelectric element (P1), and is electrically coupled to the counter electrode (3). The flexible cables (F1) include a first flexible cable (F11) connected to the power supply external electrode (4), and a second flexible cable (F12) connected to the counter external electrode (5).