In this paper, we consider the change in the directional pattern of a microstrip patch antenna located on a perfectly conducting plane and a cylinder covered with a dielectric layer. The mathematical apparatus of the Green’s tensor functions for flat and cylindrical layered metaldielectric structures is used to calculate field characteristics. The obtained results are of special interest in the design of conformal single radiators and antenna arrays located on curved surfaces that can be approximated by a cylinder, for example, the fuselage of small-sized aircraft or supports for the installation of antenna systems. It is demonstrated that the curvature of the base surface for a single element has little effect on the radiation pattern within the width of the main lobe; nevertheless, the increase in the radius of the used cylinder influences the level of the back lobe significantly.