An image forming apparatus includes a belt, plural photosensitive drums that face the belt, plural developing devices that develop plural latent images formed on the plural photosensitive drums using a developing agent, where the developing devices are disposed around the respective photosensitive drums, and plural image forming devices, where each one of the plural image forming devices includes one of the plural photosensitive drums and one of the plural developing devices, and the photosensitive drum of an adjacent one of the plural image forming devices is disposed vertically within a horizontal width of the developing device of one of the plural image forming devices.