A dielectric resonator, dielectric filter, and communication device. The dielectric resonator includes a first dielectric block, a second dielectric block, a first conductive layer, and a second conductive layer. The first dielectric block has a mounting hole, and the second dielectric block is located in the mounting hole. A dielectric constant of the second dielectric block is greater than a dielectric constant of the first dielectric block. The first conductive layer is located on at least a portion of a surface of the first dielectric block other than a surface opposite to the second dielectric block. The second conductive layer is located on at least a portion of a surface of the second dielectric block other than a surface opposite to the first dielectric block. The second conductive layer is coupled to the first conductive layer.