This application relates to components of communications devices, and in particular, to a dielectric resonator and a dielectric filter, a transceiver, and a base station to which the dielectric resonator is applied. Embodiments of this application provide a dielectric resonator and a dielectric filter, a transceiver, and a base station to which the dielectric resonator is applied. The dielectric resonator includes a metal cavity and a dielectric block that is disposed in the metal cavity and that is made from a solid-state dielectric material; where sizes of the dielectric block meet c