A monocone antenna is a type of monopole antenna with wideband characteristics. In this paper, a low-profile and small monocone antenna is proposed, by loading a circular plate and three oblique short elements. The characteristics of the proposed antenna are analyzed via simulation. Consequently, a low-profile and small monocone antenna can be obtained while maintaining the wideband characteristics. The relative bandwidth of the proposed antenna (voltage standing wave ratio (VSWR) ≤ 2) is greater than 158.9%. The frequency band of digital terrestrial television broadcasting and the mobile communication systems (from 470 to 3600MHz) in Japan can be completely covered with VSWR ≤ 2. In addition, the radiation patterns of the proposed antenna are omni-directional. The proposed antenna is prototyped, and the validity of the simulation is verified through measurement.