The application provides an antenna and a communications device, and pertains to the field of antenna technologies. The antenna includes a horizontally polarized antenna and a vertically polarized antenna that are disposed in a superposition manner. The horizontally polarized antenna includes a metal sheet, and the metal sheet can be separately connected to a double-sided parallel strip line in the horizontally polarized antenna and a first conductor of a coaxial cable. A diameter of a maximum inscribed circle of the metal sheet is greater than a line width of the double-sided parallel strip line, and both the metal sheet and the coaxial cable are located on a first side of a substrate. Therefore, the metal sheet can effectively suppress an induced current in the coaxial cable, and impact of the induced current on the vertically polarized antenna can be reduced.