One aspect of an electric actuator of the disclosure includes: a motor having a motor shaft rotating about a central axis; a speed reduction mechanism connected to a portion on one side in an axial direction of the motor shaft; a case accommodating the motor and the speed reduction mechanism; an output part to which rotation of the motor shaft is transmitted via the speed reduction mechanism; a rotation detector having a rotation sensor detecting rotation of the output part; and a wiring member electrically connected with the rotation sensor. The case has a first concave part located on an outer surface of the case. One end part of the wiring member penetrates the case from inside the case and protrudes inside the first concave part. The rotation sensor is located inside the first concave part and connected with one end part of the wiring member.