The invention discloses an image reading device and an image forming apparatus. The image reading device includes a reading unit, a first correcting unit, and a second correcting unit. The reading unit includes multiple read pixel-arrays and converts a signal charge obtained from pixels in each read pixel-array to an electric signal and outputs the electric signal as a read signal of each read pixel-array. The first correcting unit individually delays the read signals of the respective read pixel-arrays output from the reading unit so as to correct misregistration of the read signals. The second correcting unit corrects the misregistration of the read signals of the respective read pixel-arrays corrected by the first correcting unit by performing a two-point interpolation process so that a correction amount for the read signal of one specific read pixel-array among the multiple read pixel-arrays is not smaller than a correction amount for the read signal or signals of the remaining read pixel-array or pixel-arrays.