Abstract: A wireless power supply apparatus used for an aquarium includes a first casing and a second casing. The first casing is provided with a wireless power supply unit and a first retaining member. The second casing is provided with a wireless power receiving unit and a second retaining member. The wireless power supply unit and the wireless power receiving unit are electrically with a power device and a load device respectively, and are mounted to the outer side and the inner side of the aquarium through the first retaining member and the second retaining member respectively. Through the wireless power supply unit to transmit electric energy to the wireless power receiving unit instead of wiring, the present invention is waterproof and can be installed easily to enhance the appearance of the aquarium.