A screw-mount lens barrel includes a screw mount cylinder which is screw-engaged with a screw mount of a camera body, a shift ring which is rotatably supported by the screw mount cylinder to be coaxial therewith, a lens barrel body which supports an optical system and is adjustable relative to the shift ring in a direction orthogonal to an optical axis, and a shift adjustment mechanism for adjusting a position of the lens barrel body relative to the shift ring in directions orthogonal to the optical axis.