A lens barrel includes a drive ring having a hollow cylindrical shape and a gear by which the drive ring is configured to rotate around an optical axis, and a lens holder configured to move in an optical axis direction relative to the drive ring and to hold a lens and located inside of the drive ring, the lens holder including an arm extending to outside of the drive ring. The drive ring has a notch that extends in a circumferential direction of the drive ring so that the notch cannot overlap the gear. The arm of the lens holder is configured to enter and retreat from the notch of the drive ring.