This paper presents an innovative hybrid analytic-numerical approach to modelling species transport in fuel cells suitable for application on the system level. The core principle of this modelling approach is taking 1D numerical model for gas-flow and superimposing onto it a 2D analytic solution for concentration distribution in the plane perpendicular to the gas-flow together giving a 3D information on species concentration in the fuel cell. A hybrid analytic numerical model of a simple geometry isothermal fuel cell is presented and comparatively evaluated by benchmarking it against a professional full 3D CFD simulation tool. This evaluation shows very close agreement with the benchmarking 3D CFD simulation and computational times comparable to 1D models. This computational efficiency originates in the model's analytic nature in the other two dimensions making it suitable for system level application. The paper features an extensive appendix with a comprehensive detailed mathematical derivation of the hybrid analytic-numerical model. (C) 2013 Elsevier B.V. All rights reserved.