An optical writing device includes two or more light sources. The two or more light sources can be driven independently, are placed away from each other in a sub-scanning direction of a photoreceptor, and each distance of beams emitted from the light sources to the photoreceptor is different. A phase control unit causes a difference in phase among timing control data of two or more beams emitted from the two or more light sources by a phase change amount, which is determined on the basis of beam position of the each beam on the photoreceptor in a main scanning direction and varies depending on the beam position. The modulating unit modulates the timing control data of the respective phase-controlled beams by a same clock.