A developing cartridge includes a housing configured to accommodate a developing agent and including a first frame and a second frame, a developing agent carrying member rotatable on an axial line and configured to carry the developing agent, and a layer thickness regulating member configured to regulate a layer thickness of the developing agent carried by the developing agent carrying member. The first frame has a first facing surface facing the layer thickness regulating member. The second frame has a second facing surface facing the layer thickness regulating member. A welded region where the first frame and the second frame are welded and include a first welded portion extending from the first facing surface in a first direction intersecting with and away from the first facing surface, and a second welded portion extending from the first welded portion inward in a second direction intersecting with the first direction.