This paper provides detailed analytical modeling and finite elements method (FEM) analysis of the thermal behavior of the medium frequency transformer (MFT). A comprehensive analytical model in form of a thermal network consisting of conduction, convection and radiation thermal resistances is generated based on the transformer physical structure, thus allowing for fast optimization of the MFT design in terms of hot-spot temperatures. The derived analytical models are benchmarked and verified against FEM models and measurements obtained from the developed MFT prototype.