Nanostructured cobalt selenide films with honeycomb-like morphology were successfully fabricated on FTO glass by a facile electrodeposition method at ambient temperature. Such porous structure generated by randomly intersectant freboldite cobalt selenide nanosheets led to high concentration of active sites and better porosity accessible to the electrolyte, delivering superior electrocatalytic performance for the triiodide reduction. It was demonstrated that the nanostructured cobalt selenide films yielded comparable energy conversion efficiency to noble metal Pt electrode as the counter electrode in dye sensitized solar cells.