A process cartridge includes a photosensitive cartridge that has a photosensitive drum and a developing cartridge that is detachably mounted on the photosensitive cartridge. The developing cartridge includes a developing roller, an input gear, and a transmission gear. The developing gear supplies toner to the photosensitive drum. The input gear includes a contact portion that is in contact with a coupling member to receive the driving force and a gear portion. The input gear rotates about a rotational axis defining an axial direction when the contact portion receives the driving force. The transmission gear is meshingly engaged with the gear portion to transmit the driving force from the input gear to the developing roller. The gear portion has a pitch circle defined by being meshingly engaged with the transmission gear. The pitch circle of the gear portion is arranged to overlap with the contact portion in the axial direction of the input gear.