A joint compound application assembly for applying joint compound on drywall includes a rod that has a conduit integrated therein. The conduit is fluidly coupled to a source of joint compound thereby facilitating the joint compound to be urged through the conduit. A box is coupled to the rod and the box has a bottom end that is open into an interior of the box. A spray bar is fluidly coupled to the conduit and the spray bar is directed toward the bottom end of the box to spray the joint compound onto a wall or ceiling. A knife is coupled to the box to smooth the joint compound on the wall or ceiling.