The lens device includes an imaging lens and a controller. The imaging lens includes a focusing lens group which moves during focusing and an aberration correction lens group having a refractive power lower than a refractive power of the focusing lens group having the lowest refractive power. The controller adjusts a position of the aberration correction lens group relative to the focusing lens group of which focus sensitivity is maximized according to a changed condition. A predetermined conditional expression related to the focus sensitivity of the focusing lens group is satisfied.