There is provided a wide-angle lens system having a wide angle of view and less distortion. The wide-angle lens system including: an object-side lens group disposed at an object side with respect to an aperture stop and having overall positive refractive power; and an image-side lens group disposed at an image side with respect to the aperture stop and having overall positive refractive power, wherein a focal length ratio between the object-side lens group and the image-side lens group satisfies following condition 1, 2 0) and FI is a focal length of the image-side lens group (FI>0). This wide-angle lens system sufficiently corrects distortion even in a wide angle of view, thereby ensuring an image with superior quality.