A lens barrel includes: a lens frame retaining at least one portion of the plurality of lens groups; a first lens cylinder supporting the lens frame inside thereof and including a plurality of cam followers on an outer circumferential section thereof; and a second lens cylinder including a mutually parallel plurality of cam grooves in an inner circumferential section thereof and storing the firstlens cylinder therein in the collapsed state, the plurality of cam grooves are engaged with the plurality of cam followers and configured to advance and retire the first lens cylinder in a direction of an optical axis by a relative rotation of the first lens cylinder, the plurality of cam grooves have a first cam groove and a second cam groove, the plurality of cam followers have a first cam follower and a second cam follower, the first cam follower and the second cam follower are engaged with the first cam groove and the second cam groove, respectively, and the first cam follower and the second cam follower are disposed in positions mutually different relative to the direction of the optical axis.