A lens barrel includes a lens group having at least two lenses, a lens holding frame configured to hold the lens group, a holding cylinder configured to hold the lens holding frame movably in an optical axis direction of the lens group, a forward-backward moving mechanism configured to move the lens holding frame forward and backward with respect to the holding cylinder, first to third guide shafts fixed on the holding cylinder so as to surround the lens holding frame and each extend in the optical axis direction, and a biasing mechanism configured to be held by the lens holding frame between the first guide shaft and the lens holding frame and bias the lens holding frame in a direction so as to separate the lens holding frame from the first guide shaft toward the second and third guide shafts on a plane orthogonal to the optical axis direction.