A variable magnification optical system includes, in order from the object side: a positive first lens group; a negative second lens group; a positive third lens group; a negative fourth lens group; and a positive fifth lens group. When changing magnification from the wide angle end to the telephoto end, the first and third lens groups are fixed with respect to an image formation plane, the second lens group moves toward the image side, the fourth lens group moves, and the distance between the fourth and fifth lens groups changes. A rearward lens group constituted by the third, fourth, and fifth lens groups has a positive refractive power throughout the variable magnification range. The transverse magnification ratio of the fourth lens group when focused on an object at infinity is negative throughout the variable magnification range.