To provide an oscillating actuator which is capable of easily changing an oscillation start position of a shaft. An oscillating actuator includes an actuator main body 2 having a shaft 4 which is configured to oscillate about an axis L in a predetermined range of angle by means of a compressed air, and a fixing plate 3 for fixing the actuator main body 2 to a load device 30, wherein the actuator main body 2 and the fixing plate 3 are connected together by a connection mechanism 5 so as to be displaceable relative to each other in the rotation direction of the shaft 4 so that an oscillation start position A of the shaft 4 is changed by displacement of the actuator main body 2 and the fixing plate 3 relative to each other.