Provided is a zoom lens system including, in order from an object side to an image side: a first lens unit having positive refractive power; a second lens unit having negative refractive power; a prism for bending an optical path; and a rear group including a plurality of lens units, in which the first lens unit is moved to the object side while the second lens unit is moved to the image side with respect to an imaging plane at a telephoto end compared to at a wide angle end, and movement amounts M1 and M2 of the first lens unit and the second lens unit with respect to an image plane in zooming from the wide angle end to the telephoto end, a focal length f2 of the second lens unit, and a focal length ft of an entire system at the telephoto end are respectively set appropriately.