A lens barrel includes a rotational ring, first and second movable members linearly movable having first and second followers, respectively; and first and second guide grooves formed on the rotational ring, the first and second followers being slidably engaged therein, respectively. The first movable member has a non-linear moving path. The first guide groove includes an inclined linear lead groove. The lens barrel includes a complementary cam mechanism for controlling the rotational ring to define a non-linear moving path of the first movable member via a cam track of the complementary cam mechanism and a track of the linear lead groove. The second guide groove includes first and second lead groove portions extending parallel to the linear lead groove at different positions in the optical axis direction, and a differential groove portion extending in the circumferential direction which connect the first and second lead groove portions.