An image forming apparatus includes a housing, a top cover having an opening, a process cartridge attachable to the housing, a toner cartridge attachable to the process cartridge, and an interlocking mechanism. The top cover is pivotally movable between a first position closing the opening and a second position opening the opening. In a state where the toner cartridge is attached to the process cartridge, the toner cartridge is pivotally movable between an attachment/detachment position where the toner cartridge is attachable to and detachable from the process cartridge; and a fixed position where the toner cartridge is fixed to the process cartridge. The interlocking mechanism is configured to pivotally move the toner cartridge to the attachment/detachment position when the top cover is moved to the second position, and to pivotally move the toner cartridge to the fixed position when the top cover is moved to the first position.