In the previous chapters, details about the relations between a power transformer operational specification and its design details—including dimensions, materials used and their specifications, window relative dimensions and area occupied by the copper windings—have been discussed. Moreover, conventional design approaches that guarantee fulfilling a set of required specifications have been presented. In this chapter, however, a couple of unconventional computer-aided-design (CAD) approaches are presented. Namely, this chapter discusses how artificial neural networks (ANNs) and the multi-objective particle swarm optimization (MOPSO) approach may be utilized to design a power transformer while minimizing the expertise required to do so. More details on how to utilize both approaches in unconventional design methodologies of power transformers, together with numerical examples, are presented in the sections of this chapter.