A developing device is provided. The developing device includes: a rotatable developer carrier which is configured to carry developer; a housing including a first resin frame which includes a pair of sidewalls supporting both end portions of the developer carrier in a rotational axial direction thereof, and a second resin frame which is connected to the first resin frame; and a receiving-side coupling member which is provided rotatably to one of the sidewalls and is configured to couple with a driving-side coupling member in the rotational axial direction to transmit driving force to the developer carrier. The receiving-side coupling member is overlapped with a connection part between the first frame and the second frame as viewed from the rotational axial direction.