The frame of the automobile vehicle seat back comprises a body extending over a general plane and functional components joined to the body, serving notably to attach or reinforce it. It is made in one piece from an overmoulded plastic material that forms the body, reinforced by a reinforcing strip comprising a woven band of mineral and plastic material fibers, the reinforcing strip extending in the general plane of the frame and interconnecting at least two of the functional components comprising inserts at least partially embedded in the body.