A survey of multi-resonant antennas is comprehensively presented, with emphasis on theoretical framework, design approaches, and practical examples. This article begins with a brief history of the multi-resonant dipole theory, and then concentrates on the design approaches that have been developed to typical, basic antenna elements, for example, electric dipole antenna, slotline antenna, loop antenna, complementary dipole antenna, and microstrip patch antenna. Design examples for different practical applications are then raised. In final, the multi-resonant antenna design approach is summarized and compared to some relevant antenna design techniques.