An antenna mounting bracket is disclosed for mounting an antenna within a water meter container. The mounting bracket comprises a first plate having a top surface, a bottom surface, a front edge and a rear edge. A first elongated aperture and a first slit traverse through the first plate. A first step is secured to the rear edge of the first plate for supporting the first plate upon the lip of the water meter container. A second plate defines a top surface, a bottom surface, a front edge and a rear edge. A second elongated aperture and a second slit traverse through the second plate. A second step is secured to the rear edge of the second plate for supporting the second plate upon the lip of the water meter container. The bottom surface of the first plate slidably engages adjacent to the top surface of the second plate with the first step being a mirror image of the second step for defining an adjustable bracket length. The first elongated aperture overlays the second elongated aperture for defining an adjustable elongated aperture. The first slit overlays the second slit for defining an adjustable slit. A fastener traverses through the adjustable slit for securing the first plate to the second plate after setting the adjustable bracket length to equal the water meter container. The adjustable elongated aperture engages the antenna for positioning the antenna above the water meter.