An image forming apparatus includes: a housing having an opening; a drawer movable, through the opening, between a housing position in which the drawer is housed in the housing and a drawn position in which the drawer is drawn from the housing; a first drum cartridge including a first photosensitive drum, and mountable to and removable from the drawer; a first developing cartridge including a first developing roller, and mountable to and removable from the first drum cartridge; and a transfer device configured to transfer toner on the first photosensitive drum to a sheet and located above the first drum cartridge in a state where the first drum cartridge is mounted to the drawer and the drawer is located in the housing position. In a state where the first drum cartridge is removed from the drawer, the first developing cartridge is mountable to and removable from the first drum cartridge.