This application provides an antenna and a communication device. The antenna includes a first signal cable configured to transmit a first signal, a second signal cable, a combining unit, a combined transmission line, a plurality of first filter units, and a plurality of cavities. The first signal cable and the second signal cable are connected to the combined transmission line through the combining unit. The plurality of first filter units are each electrically connected to the first signal cable and are respectively located in at least two different cavities. The first filter units are configured for filtering to ensure transmission quality of the first signal. According to the antenna provided in this application, the plurality of first filter units are distributed in different cavities. In this way, a size of each of the cavities is small. In addition, the plurality of first filter units can filter out an interference signal with a wide bandwidth, or in other words, an interference signal is filtered out more completely, thereby improving a filtering effect. Moreover, the cavities are cavities of the antenna, and no additional cavities are separately provided, so that costs and space of the antenna can be reduced.