Transfer function models for the descriptionof physical systems have recently been introduced to the field of multidimensional digital signal processing. They provide an alternative to the conventional representation by partial differential equations (PDE) and are suitable for computer implementation. This paper extends the transfer function approach to vector PDEs. They arise from the physical analysis of multidimensional systems in terms of potential and flux quantities. Expressing the resulting coupled PDEs in vector form facilitates the direct formulation of boundary and interface conditionsin their physical context. It is shown how a carefully constructed transformation for the space variable leads to transfer function models for vector PDEs. They are the starting point for the derivation of discrete models by standard methods for one-dimensional systems. The presented functional transformation approach is suitable for a number of technical applications, like electromagnetics, op...