A handset antenna modeling and design technique using space mapping (SM) is presented. Thin-wire models are exploited as coarse models in the SM algorithms, while the fine models are high-accuracy electromagnetic simulations. The thin-wire models capture the basic physics of handset antennas but are not as accurate as the fine model. On the other hand, they are computationally cheap when analyzed by the method of moments solvers. Detailed guidelines for building thin-wire models are provided. Two SM algorithms are employed: 1) implicit, input and output space mapping and 2) implicit and output space mapping. An internal dual-band patch antenna and an arm-folded planar inverted F antenna are designed through our approach. For comparison, direct optimizations have been performed in each example.