An image sensor includes first pixels and second pixels arranged in alternating order along a first direction, first output lines extending in a second direction that is perpendicular to the first direction and respectively connected to the first pixels, second output lines extending in the second direction and respectively connected to the second pixels, first analog circuit blocks and second analog circuit blocks arranged in alternating order along the first direction, and shielding structures disposed each between adjacent ones of the first and second analog circuit blocks. Each of the first analog circuit blocks includes a plurality of first analog circuits respectively connected to the first output lines. Each of the second analog circuit blocks includes a plurality of second analog circuits respectively connected to the second output lines.