As an alternative to traditional reactant flow field design, interdigitated flow field configuration is also of interest to fuel cell design engineers and academic researchers. In this work, the two-phase flow behavior inside the cathode of an interdigitated proton exchange membrane fuel cell, including both gas flow channel and porous gas diffusion layer, is numerically studied. The effects of variable design and operational parameters, including channel surface wettability and operating pressure, on water behavior are investigated. A Darcy’s law based porous media model is used for the simulation of the two-phase transport inside the cathode gas diffusion layer, and some interesting two-phase behaviors, such as liquid water distribution under different operating condition, are observed. Compared with the water transport characteristics of a serpentine flow field, the current study shows significant difference for an interdigitated configuration, in terms of two-phase water transport. Although the interdigitated design is generally not considered viable for practical applications in fuel cell, it does provide a convenient platform for fundamental studies of multiphase transport and valuable insights in fuel cell design and optimization.