An image reading apparatus includes a sheet conveyance path on which a sheet of a document from which an image is to be read is conveyable; a light source that emits light to be irradiated on the sheet; a conductive unit through which heat generated at the light source is transferable; and a heat radiating unit that forms a part of the sheet conveyance path, through which the heat transferred from the light source to the conductive unit is propagable, and that radiates the heat propagated from the conductive unit to air flowing in the sheet conveyance path when the sheet is being conveyed.