A chip antenna and an antenna apparatus, which allow the resonance frequency of the antenna to be set with a high degree of freedom, include a feeding electrode formed on the bottom surface, fourth side surface, and top surface of a dielectric substrate, a non-feeding electrode formed on the bottom surface, third side surface, and top surface of the dielectric substrate, wherein the leading ends of the feeding electrode and the non-feeding electrode are facing each other with a predetermined distance therebetween on the top surface of the dielectric substrate. The chip antenna and antenna apparatus further include a frequency adjusting electrode formed on the first side surface of the dielectric substrate, and ground electrodes connected to ground electrodes of a circuit substrate on which the chip antenna is mounted, wherein the ground electrodes are electrically connected to the frequency adjusting electrode and are formed on the bottom surface of the dielectric substrate.