A lens device includes: a movable lens capable of being moved in a direction of an optical axis and configured to be moved by an operating member driven by an operating member driving unit; an optical member that reflects a portion of light having passed through the movable lens; a target position information acquiring unit that acquires information of a target position of the movable lens by calculating the target position based on the reflected light; and a movable lens driving unit that performs first driving for moving the movable lens based on a position of the operating member detected by an operating member position detection unit, and the operating member driving unit drives the operating member based on the information of the target position.