A cable supporting device can suppress a coil spring from protruding toward an inner circumferential side of a tubular portion of a main body, and can apply, to a nut member, a rotational force in a direction toward a stopper. The cable supporting device includes: a main body including a tubular portion in which a through hole is formed and on which an external thread is formed; a nut member; a stopper arranged on one side in the first direction with respect to the external thread and opposed to the nut member; and a coil spring applying, to the nut member, a rotational force in a direction approaching the stopper. An engagement portion that engages a first end portion of the coil spring is formed in the nut member, and an insertion groove is formed on the outer circumferential surface of the tubular portion.