An actuator for connecting and disconnecting a dog clutch between two coaxial shafts (1, 2) by means of an axially movable clutch sleeve (3) comprises an electric motor. A motor shaft (8) of the motor is connected to a rotatable actuator rod (7). This rod (7) is provided at its end with an eccentric pin (5) for such cooperation with the clutch sleeve (3) that a rotation of the actuator rod (7) 180° or less by means of the motor from a rotational position corresponding to one axial end position of the clutch sleeve (3) to a rotational position corresponding to the other axial end position of the clutch sleeve (3) leads to a connection or disconnection of the dog clutch.