A lens barrel includes a housing having a ring portion surrounding an optical axis; a first optical element and a second optical element which are positioned inside the ring portion and which are movable along the optical axis relative to the housing; a support frame which supports the second optical element, and has at least one arm portion which projects radially outwards to such an extent that an outer end of the arm portion is positioned radially outside the ring portion of the housing; and at least one guide shaft positioned radially outside the ring portion, and configured to guide the arm portion in the optical axis direction.